《C語言程序設(shè)計教程》例題源碼

C語言程序設(shè)計教程》例題源碼練習(xí)一【例1．1】打印“常熟理工學(xué)院”的漢語拼音。程序源碼如下：voidmain(){printf(“changshuligongxueyuan!”);}【例1．2】求任意兩個整數(shù)的積。程序源碼如下：#include<stdio.h>intmul(inta,intb);voidmain(){intx,y,z;printf("inputtwonumbers:\n");scanf("%d%d",&x,&y);z=mul(x,y);printf("mul=%d",z);}intmul(inta,intb){intc;c=a*b;returnc;}【例1．3】求整數(shù)a、b的和。程序源碼如下：voidmain(){inta,b;intsum;scanf(“%d,%d”,&a,&b);sum=a+b;printf(“%d”,sum);練習(xí)二【例2．1】轉(zhuǎn)義字符的使用。程序源碼如下：voidmain(){printf("\x4f\x4b\x21\n");printf("\112\112\132\104\n");}【例2．2】符號常量的使用。程序源碼如下：#definePI3.14159265voidmain(){floatr,m,s;r=1.2;m=2*PI*r;s=PI*r*r;printf("%f,%f",m,s);}例2．3】整型變量的定義與使用程序源碼如下：voidmain(){intx,y,m;unsignedu,n;x=30;y=18;u=32800;m=x+y;n=y+u;printf("x+y=%d,y+u=%d\n",m,n);}例2．4】整型變量的定義與使用。程序源碼如下：voidmain(){inta,b,c,d;longx,y;x=7;y=8;a=9;b=10;c=x+a;d=y+b;printf("c=x+a=%d,d=y+b=%d\n",c,d);}例2．5】整型數(shù)據(jù)的溢出程序源碼如下：voidmain(){intx,y;x=32767;y=x+1;printf("%d,%d\n",x,y);}例2．6】實型變量的定義和應(yīng)用舉例程序源碼如下：voidmain(){floatx,y,z,a,b;x=1234.2345;a=0.02;y=1111111.11111111111;z=x+y;b=a+y;printf("%f\n%f\\n",z,b);}例2．7】字符型變量的定義與使用舉例程序源碼如下：voidmain(){charc1,c2;c1=97;c2=98;printf("%c%c",c1,c2);printf("%d%d\n",c1,c2);c1=c1-32;c2=c2-('a'-'A');printf("%c%c\n",c1,c2);}【例2．8】變量初始化舉例。程序源碼如下：voidmain()intc1,c2,c3,c4;c1=7;c2=7;c3=3;c4=4;printf("%d%d",c1,c2);printf("%d%d\n",c3,c4);}等效于voidmain(){intc1=7,c2=7,c3=3,c4=4;printf("%d%d",c1,c2);printf("%d%d\n",c3,c4);}【例2．10】強(qiáng)制類型轉(zhuǎn)換。程序源碼如下：voidmain(){floatm=6.5;intn;n=(int)m;printf("%f,%d",m,n);}練習(xí)三【例3．1】關(guān)系表達(dá)式實例。程序源碼如下：#include<stdio.h>intvoidmain(){inttrue,false;true=(3>2);false=(3==2);printf("true=%d;false=%d\n",true,false);return0;}【例3．2】邏輯運(yùn)算符實例。程序源碼如下：voidvoidmain(){charc='k';inti=1,j=2,k=3;floatx=3e+5,y=0.85;printf("%d,%d\n",!x*!y,!!!x);printf("%d,%d\n",x||i&&j-3,i<j&&x<y);printf("%d,%d\n",i==5&&c&&(j=8),x+y||i+j+k);}【例3．3】自增、自減運(yùn)算符實例。程序源碼如下：#include<stdio.h>voidvoidmain(){inti=8;printf("%d\n",++i);printf("%d\n",--i);printf("%d\n",i++);printf("%d\n",i--);printf("%d\n",-i++);printf("%d\n",-i--);}【例3．4】自增、自減運(yùn)算符實例。程序源碼如下：#include<stdio.h>voidvoidmain(){inti=5,j=5,p,q;p=(i++)+(i++)+(i++);q=(++j)+(++j);printf("%d,%d,%d,%d",p,q,i,j);}【例3．5】輸出兩個數(shù)中的大數(shù)。程序源碼如下：#include<stdio.h>voidvoidmain(){inta,b,max;printf("\ninputtwonumbers:");scanf("%d%d",&a,&b);printf("%d",max=a>b?a:b);}【例3．6】逗號運(yùn)算符實例。程序源碼如下：#include<stdio.h>voidvoidmain(){inta=2,b=4,c=6,x,y;y=((x=a+b),(b+c));printf("y=%d,x=%d",y,x);}練習(xí)四【例4.5】求1X2X3X4X5的算法，用C語言表示。程序源碼如下：#include<stdio.h>voidmain(){inti,t;t=1;i=2;while(i<=5){t=t*i;i=i+1;}printf(“%d”,t);}【例4.6】printf函數(shù)使用實例。程序源碼如下：#include<stdio.h>voidvoidmain(){inta=88,b=89;printf("%d%d\n",a,b);printf("%d,%d\n",a,b);printf("%c,%c\n",a,b);printf("a=%d,b=%d",a,b);}【例4.7】printf函數(shù)應(yīng)用實例。程序源碼如下：#include<stdio.h>voidvoidmain()inta=15;floatb=138.357620;doublec=35648256.3645287;chard='p';printf("a=%d,%5d,%o,%x\n",a,a,a,a);printf("b=%f,%lf,%5.4lf,%e\n",b,b,b,b);printf("c=%lf,%f,%8.4lf\n",c,c,c);printf("d=%c,%8c\n",d,d);}【例4．8】printf函數(shù)應(yīng)用實例。程序源碼如下：#include<stdio.h>voidmain(){inti=8;printf("%d\n%d\n%d\n%d\n%d\n%d\n",++i,--i,i++,i--,-i++,-i--);}【例4．9】printf函數(shù)應(yīng)用實例。程序源碼如下：#include<stdio.h>voidmain(){inti=8;printf("%d\n",++i);printf("%d\n",--i);printf("%d\n",i++);printf("%d\n",i--);printf("%d\n",-i++);printf("%d\n",-i--);}【例4．10】putchar函數(shù)應(yīng)用實例。程序源碼如下：#include<stdio.h>voidvoidmain(){chara='B',b='o',c='k';putchar(a);putchar(b);putchar(b);putchar(c);putchar('\t');putchar(a);putchar(b);putchar('\n');putchar(b);putchar(c);}【例4．11】scanf函數(shù)應(yīng)用實例。程序源碼如下：#include<stdio.h>voidvoidmain(){inta,b,c;printf("inputa,b,c\n");scanf("%d%d%d",&a,&b,&c);printf("a=%d,b=%d,c=%d",a,b,c);}【例4．12】格式字符串應(yīng)用實例。程序源碼如下：#include<stdio.h>voidvoidmain(){chara,b;printf("inputcharactera,b\n");scanf("%c%c",&a,&b);printf("%c%c\n",a,b);}【例4．13】格式字符串應(yīng)用實例。程序源碼如下：#include<stdio.h>voidvoidmain(){chara,b;printf("inputcharactera,b\n");scanf("%c%c",&a,&b);printf("\n%c%c\n",a,b);}【例4.14】輸入一個小寫字母,輸出其ASCII碼和對應(yīng)的大寫字母。程序源碼如下：#include<stdio.h>voidvoidmain()chara;printf("inputacharacter:\n");a=getchar();printf("%d\n",a);putchar(a-32);}【例4．15】輸入三角形的三邊長，求三角形面積。程序源碼如下：#include<stdio.h>#include<math.h>voidmain(){floata,b,c,s;doublearea;scanf(“%f,%f,%f”,&a,&b,&c)s=1.0/2*(a+b+c);area=sqrt(s*(s-a)*(s-b)*(s-c));printf(“a=%7.2f,b=%7.2f,c=%7.2f,s=%7.2f\n”,a,b,c,s)printf(“area=%7.2f\n”,area)}練習(xí)五【例5．1】輸入兩個數(shù)到變量x和y中，如果x>y則輸出x。程序源碼如下：#include<stdio.h>voidmain(){intx,y;printf("pleaseinputx,y:");scanf("%d,%d",&x,&y);if(x>y)printf("x>y\n");printf("%d,%d\n",x,y);}【例5．2】某應(yīng)用軟件的登錄密碼是123，用戶從鍵盤輸入密碼，如果正確則顯示“歡迎使用本軟件”的字樣，如果密碼錯誤則顯示“密碼錯，請重新輸入！”的字樣。#include<stdio.h>voidmain()intpassword;printf("請輸入密碼：\n");scanf("%d",&password);if(password==123)printf("歡迎使用本軟件！”)；elseprintf("密碼錯，請重新輸入！”)；}注意：本題要啟動中文DOS運(yùn)行環(huán)境，否則程序中的漢字將顯示為亂碼，以下例題如有漢字輸入輸出均與此相同，不再多述。【例5.3】編程實現(xiàn)以下問題求解：給出一百分制成績，要求輸出成績等級A、B、C、D、E。設(shè)90分以上為A，80?89分為B，70?79分為C，60?69分為D，60分以下為E。程序源碼如下：#include<stdio.h>voidmain(){intscore；printf("請輸入成績：")；scanf("%d",&score)；printf("score=%d：",score)；if(score>=90)printf("A\n")；elseif(score>=80)printf("B\n")；elseif(score>=70)printf("C\n")；elseif(score>=60)printf("D\n")；elseprintf("E\n")；}【例5.4】從鍵盤上輸入3個實數(shù)a、b、c,求出其中的最小值并輸出。程序源碼如下：#include<stdio.h>voidmain(){floatx,y,z,min；printf("請輸入x,y,z：");scanf("%f,%f,%f",&x,&y,&z)；if(x<y){if(x<z)min=x；elsemin=z；}else{if(y<z)min=y;elsemin=z;}printf("min=%f\n",min);}【例5．5】從鍵盤上輸入一個字母，如果這個字母是小寫字母就將它轉(zhuǎn)換成大寫字母程序源碼如下：#include<stdio.h>voidmain(){charx;printf("請輸入一個字母：”)；scanf("%c",&x);x=(x>=a&&x<=z)?(x-32):x;/*大小寫字母ASCII碼值相差32*/printf(”轉(zhuǎn)換成大寫為：%c\n",x);}【例5.6】設(shè)計一個程序，要求輸入數(shù)字1,顯示Monday,輸入數(shù)字2,顯示Tuesday ,一直到輸入數(shù)字7,顯示Sunday，除此以外，顯示error。程序源碼如下：#include<stdio.h>voidmain(){intx;printf("inputintegernumber:");scanf("%d",&x);switch(x){case1:printf("Monday\n");break;case2:printf("Tuesday\n");break;case3:printf("Wednesday\n");break;case4:printf("Thursday\n");break;case5:printf("Friday\n");break;case6:printf("Saturday\n");break;case7:printf("Sunday\n");break;default:printf("error\n");【例5.7】編程序?qū)崿F(xiàn)輸入不同的月份輸出相應(yīng)的季節(jié)。按農(nóng)歷一般規(guī)定1?3月為春季，4?6月為夏季，7?9月為秋季，10?12月為冬季。程序源碼如下：#include<stdio.h>voidmain(){intmonth;printf("\n請輸入月份：");scanf("%d",&month);switch(month){case1:case2:case3:printf("春季！\n");break;case4:case5:case6:printf("夏季！\n");break;case7:case8:case9:printf("秋季！\n");break;case10:case11:case12:printf("冬季！\n");break;default:printf("輸入的數(shù)據(jù)非法！\n");}}【例5.8】編程實現(xiàn)一個能進(jìn)行加減乘除運(yùn)算的簡易計算器程序。程序源碼如下：#include<stdio.h>voidmain(){floata,b;charch;printf("inputexpression:a+(-,*,/)b\n");scanf("%f%c%f",&a,&ch,&b);switch(ch){case printf("resultis%f\n",a+b); break;case printf("resultis%f\n",a-b); break;case printf("resultis%f\n",a*b); break;caseif(b!=0)printf("resultis%f\n",a/b);elseprintf("除數(shù)為0！\n");break;default:printf("inputerror\n");}}練習(xí)六例6．1】利用if-goto循環(huán)結(jié)構(gòu)求解1到100的累加和程序源碼如下：#include<stdio.h>voidmain(){intn=1,s=0;loop:s=s+n;n++;if(n<=100)gotoloop;printf("s=%d\n",s);}【例6．2】用for循環(huán)解決1到100的累加問題。程序源碼如下：#include<stdio.h>voidmain(){inti,s=0;for(i=1;i<=100;i++)s=s+i;printf("s=%d\n",s);}【例6.3】求數(shù)學(xué)公式的和：s=l+3+5+?+99。程序源碼如下：#include<stdio.h>voidmain(){ints=0,i;for(i=1;i<=99;i=i+2){s=s+i;printf("i=%d\ts=%d\n",i,s);【例6．4】求n的階乘n!(n!=1*2*??*n)。程序源碼如下：#include<stdio.h>voidmain(){inti,n;longresult=1;printf(“inputn:”);scanf(“%d”,&n);for(i=1;i<=n;i++)result=result*i;printf("%d!=%ld\n",n,j);}【例6．5】從鍵盤上輸入10個數(shù)，求其平均值。程序源碼如下：#include<stdio.h>voidmain(){inti;floatf,sum;for(i=1,sum=0.0;i<11;i++){scanf("%f",&f);sum=sum+f;}printf("average=%f\n",sum/10);}【例6．6】從鍵盤上輸入若干正整數(shù)，求其中最大數(shù)和最小數(shù)，輸入的數(shù)以0為中止標(biāo)記。程序源碼如下：#include<stdio.h>voidmain(){intx,max,min;scanf("%d",&x);max=min=x;for(;x!=0;){if(x<min)min=x;if(x>max)max=x;scanf("%d",&x);}printf("max=%dmin=%d\n",max,min);}【例6．7】國際象棋棋盤有64格，若在第1格放1粒谷；第2格放2粒谷；第3格放4粒谷；第4格放8粒谷??如此一直放到第64格。假設(shè)2000000粒谷有一噸重，問需要多少噸谷才夠放？程序源碼如下：#include<stdio.h>voidmain(){inti;floatn,s;i=1;n=1.0;s=1.0;for(i=2;i<=64;i++){n=n*2;s=s+n;}printf("s=%f\n",s/2000000);}【例6．8】用while語句求1到100的累加和。程序源碼如下：#include<stdio.h>voidmain(){inti=1,s=0;while(i<=100){s=s+i;i++;}printf(“s=%d\n”,s);}【例6．9】用do-while語句求1到100的累加和。#include<stdio.h>voidmain(){inti=1,s=0;do{s=s+i;i++;}while(i<=100);printf(“s=%d\n”,s);}【例6．10】從鍵盤上連續(xù)輸入若干個字符(以回車換行符為結(jié)束標(biāo)記)，統(tǒng)計字符個數(shù)(不含回車換行符)。程序源碼如下：#include<stdio.h>voidmain(){intn=0;charc;while((c=getchar())!='\n')n++;printf("numberofcharacter=%d\n",n);}程序運(yùn)行結(jié)果如下：Ruruweuiopjsbhcvgasfdugsdfg/numberofcharacter=27【例6．11】對比例10，用do-while循環(huán)結(jié)構(gòu)解決相同問題。即從鍵盤上連續(xù)輸入若干個字符(以回車換行符為結(jié)束標(biāo)記)，統(tǒng)計字符個數(shù)(不含回車換行符)。程序源碼如下：#include<stdio.h>voidmain(){intn=-1;charc;don++;while((c=getchar())!='\n');printf("numberofcharacter=%d\n",n);}【例6．12】輸入一個正整數(shù)(短整型)，計算并輸出該數(shù)的各位數(shù)字之和。反復(fù)執(zhí)行直到輸入為0時停止。程序源碼如下：#include<stdio.h>voidmain(){intx,x1,x2,x3,x4,x5;scanf("%d",&x);while(x!=0){x5=x%10;x=x/10;x4=x%10;x=x/10;x3=x%10;x=x/10;x2=x%10;x1=x/10;printf("%d\n",x1+x2+x3+x4+x5);scanf("%d",&x);}}【例6.13】令s=l+2+3+4+……+n,求出使得s的值最接近999的n值。程序源碼如下：#include<stdio.h>voidmain(){ints=0;intn=1;while(s<=999){s=s+n;n++;}n--;printf(“n=%d\n”,n);}【例6.14】要輸出五行10個星號的圖形，可以用一重循環(huán)的for語句來實現(xiàn)。程序源碼如下：#include<stdio.h>voidmain(){inti,k;for(k=1;k<=5;k++)for(i=1;i<=10;i++){printf("*");}printf("\n");}}【例6．15】打印所有水仙花數(shù)(水仙花數(shù)是各位數(shù)字立方和等于該數(shù)本身的三位正整數(shù))。程序源碼如下：#include<stdio.h>voidmain(){inti,j,k,m,n;for(i=1;i<=9;i++)for(j=0;j<=9;j++)for(k=0;k<=9;k++){m=i*i*i+j*j*j+k*k*k;n=100*i+10*j+k;if(m==n)printf("%d\n",m);}}【例6.16】從鍵盤上接收字符并顯示出來，當(dāng)按Tab鍵時結(jié)束輸入。程序源碼如下：#include<stdio.h>voidmain(){charch;for(;;){scanf("%c",&ch);if(ch==\t)break;elseprintf("%c",ch);}}【例6.17】設(shè)有一張厚0.1mm而面積足夠大的紙，如果將它不斷地對折，問對折多少次后，其厚度可達(dá)到或超過珠穆朗瑪峰的高度(8848.130米)。程序源碼如下：#include<stdio.h>voidmain(){floath=0.1;intn=0;while(h<=8848130){h=h*2;n++;}printf("itneeds%dtimes！\n",n);}【例6.18】對除了是3的倍數(shù)以外的1?100的數(shù)求和。程序源碼如下：#include<stdio.h>voidmain(){ints,i;s=0;for(i=1;i<=100;i++){if(!(i%3))continue;s=s+i;}printf("s=%d",s);}【例6.19】檢查輸入的一行字符中有無相鄰兩字符相同程序源碼如下：#include<stdio.h>voidmain(){chara,b;printf("inputastring：");b=getchar();while((a=getchar())!='\n')if(a==b){printf("thestringyouinputhavesamecharacternearby\n");break;}b=a;}}練習(xí)七【例7．1】一維數(shù)組引用的示例。程序源碼如下：#include<stdio.h>voidmain(){intnum[5],i;num[0]=5;for(i=1;i<4;i++)num[i]=i+5;printf("inputthe5thnumber:");scanf("%d",&num[4]);printf("numbersofarraynumare:\n");for(i=0;i<5;i++)printf("num[%d]=%d",i,num[i]);}【例7．2】從鍵盤上輸入10個字符，然后按相反次序輸出程序源碼如下：#include<stdio.h>voidmain(){chara[10];inti;printf("input10char:");for(i=0;i<10;i++)scanf("%c",&a[i]);printf("\n");printf("output10char:");for(i=9;i>=0;i--)printf("%c",a[i]);}程序運(yùn)行結(jié)果如下：input10char:qwertyuiop/output10char:poiuytrewq【例7．3】用“選擇排序法”對一維數(shù)組中的整數(shù)進(jìn)行從小到大的順序排列。程序源碼如下：#include<stdio.h>voidmain(){intn,i,k,x,min,min_k,a[100];printf("輸入整數(shù)個數(shù)(vlOO):");scanf("%d",&n);for(i=O;ivn;i++){printf("輸入第％小個整數(shù):",i+1);scanf("%d",&a[i]);}for(k=O;kvn-1;k++){min=a[k];min_k=k;for(i=k;ivn;i++)if(a[i]vmin){min=a[i];min_k=i;}x=a[min_k];a[min_k]=a[k];a[k]=x;}printf("輸出排序結(jié)果:”)；for(i=O;ivn;i++)printf("%d",a[i]);}【例7．4】從鍵盤輸入10個數(shù)，求其中的最大數(shù)和最小數(shù)，并按逆序打印出該數(shù)組程序源碼如下：#includevstdio.h>voidmain()floata[1O];inti;floatmax=-1e2O,min=1e2O;for(i=0;i<=9;i++)scanf("%f",&a[i]);for(i=0;i<=9;i++){if(a[i]>max)max=a[i];if(a[i]<min)min=a[i];}printf("max=%6.2f,min=%6.2f\n",max,min);for(i=9;i>=0;i--)printf("%6.2f\t",a[i]);}【例7．5】從鍵盤輸入一個3*4的整型數(shù)組，求出其中的最大值和最小值并顯示數(shù)組內(nèi)容。程序源碼如下：voidmain(){inta[3][4];inti,j,min,max;for(i=0;i<3;i++)for(j=0;j<4;j++)scanf("%d",&a[i][j]);min=a[0][0];max=a[0][0];for(i=0;i<3;i++)for(j=0;j<4;j++){if(min>a[i][j])min=a[i][j];if(max<a[i][j])max=a[i][j];}printf("max=%dmin=%d\n",max,min);for(i=0;i<3;i++)for(j=0;j<4;j++){printf("a[%d][%d]=%d\t",i,j,a[i][j]);}}【例7．6】向一個3*3的矩陣(整型數(shù)組)輸入數(shù)據(jù)，輸出對角線元素并求它們的和程序源碼如下：voidmain(){inta[3][3],sum=0;inti,j;printf("inputdata:\n");for(i=0;i<3;i++)for(j=0;j<3;j++)scanf("%d",&a[i][j]);for(i=0;i<3;i++){printf("a[%d][%d]=%d\t",i,i,a[i][i]);sum=sum+a[i][i];}printf("\nsum=%d",sum);}【例7．7】從鍵盤上輸入一個2*3的矩陣，將其轉(zhuǎn)置后形成3*2矩陣輸出。程序源碼如下：#include<stdio.h>voidmain(){inta[2][3],b[3][2],i,j;for(i=0;i<2;i++)for(j=0;j<3;j++)scanf("%d",&a[i][j]);for(i=0;i<3;i++)for(j=0;j<2;j++)b[i][j]=a[j][i];for(i=0;i<3;i++){for(j=0;j<2;j++)printf("%4d",b[i][j]);printf("\n");}}【例7．8】輸入3個學(xué)生的學(xué)號和3門課程的成績(整數(shù))，統(tǒng)計并輸出3門課程總分最高的學(xué)生的學(xué)號和總分。程序源碼如下：voidmain()ints[3][5],i,max,max_i;for(i=0;i<3;i++){printf("inputstudentno%d,s1,s2,s3:\n",i+1);scanf("%d,%d,%d,%d",&s[i][0],&s[i][1],&s[i][2],&s[i][3]);s[i][4]=s[i][1]+s[i][2]+s[i][3];}max=s[0][4],max_i=0;for(i=1;i<3;i++)if(max<s[i][4]){max=s[i][4];max_i=i;}printf("studentno=%dtotal=%d",s[max_i][0],s[max_i][4]);}【例7．9】輸出一維字符串?dāng)?shù)組的值。程序源碼如下：voidmain(){charc[10]={'I','','a','m','','a','','b','o','y'};inti;for(i=0;i<10;i++)printf("%c",c[i]);}【例7．10】輸出如下所示的圖案。*******程序源碼如下：voidmain(){chara[5][5]={'','','*','',''，，，，},'','*','*','*',''，，，，},{'*','*','*','*','*'},I， ， ， ，J?'','*','*','*',''，，，，},'','','*','',''，，，，};inti,j;for(i=0;i<5;i++)printf("\n");for(j=0;j<5;j++)}【例7．11】檢測一給定的字符串的長度(字符數(shù))，不包括結(jié)束符'\0'。程序源碼如下：voidmain(){staticcharstr[]="heisagoodstudent!";inti=0;while(str[i]!='\0')i++;printf("thelengthofstringis%d\n",i);}【例7．12】從鍵盤上輸入一行字符(不多于40個，以回車換行符作為輸入結(jié)束標(biāo)記)將其中的大寫字母改為小寫字母，其它字符不變，然后逆向輸出。程序源碼如下：voidmain(){chara[40];intn=0;printf("inputchar(<40):");do{scanf("%c",&a[n]);if(('A'<=a[n])&&(a[n]<='Z'))a[n]+=32;n++;}while(a[n-1]!='\n');n=n-2;while(n>=0)printf("%c",a[n--]);}【例7．13】從鍵盤上輸入一字符串，并將其顯示在屏幕上。程序源碼如下：#include<stdio.h>voidmain()charstr[20];inti;for(i=0;i<14;i++)scanf("%c",&str[i]);for(i=0;i<14;i++)printf("%c",str[i]);}【例7．14】從鍵盤上輸入一字符串，并將其顯示在屏幕上程序源碼如下：#include<stdio.h>voidmain(){charstr[20];scanf("%s",str);printf("%s",str);}【例7．15】從鍵盤上輸入兩個字符串，輸出其中較大者。程序源碼如下：#include<stdio.h>voidmain(){chara[80],b[80],flag='';inti=0;printf("string1:");scanf("%s",a);printf("string2:");scanf("%s",b);while((a[i]!='\0')&&(b[i]!='\0'))if(a[i]<b[i]){flag='b';break;}elseif(b[i]<a[i]){flag='a';break;}elsei++;if(flag=='')if(a[i]=='\0')flag='b';elseflag='a';if(flag=='a')elseprintf("max-string:%s\n",b);}【例7．16】編寫一程序，將兩個字符串連接起來。程序源碼如下：voidmain(){chars1[80],s2[40];inti=0,j=0;printf("inputstring1：");scanf("%s",s1);printf("inputstring2：");scanf("%s",s2);while(s1[i]!='\0')i++;while(s2[j]!='\0')s1[i++]=s2[j++];s1[i]='\0';printf("newstring：%s",s1);}練習(xí)八【例8．1】編寫程序求三個整數(shù)的最大值，其中三個整數(shù)由鍵盤輸入程序源碼如下：#include<stdio.h>intmax(intx,inty,intz){intm;if(x>y)m=x;elsem=y;if(z>m)m=z;return(m);}voidmain(){intn1,n2,n3,result;scanf("%d,%d,%d",&n1,&n2,&n3);result=max(n1,n2,n3);printf("最大值result=%d",result);}【例8.2】以下程序通過調(diào)用swap函數(shù)，對調(diào)主函數(shù)中變量x和y的值，請觀察程序的輸出結(jié)果。程序源碼如下：#include<stdio.h>floatswap(floata,floatb){floatt;printf("swap函數(shù)運(yùn)行，交換前a=%.2f,b=%.2f\n",a,b);t=a;a=b;b=t;printf("swap函數(shù)運(yùn)行，交換后a=%.2f,b=%.2f\n",a,b);return0;}voidmain(){floatx=10.0,y=20.0;printf("調(diào)用前x=%.2f,y=%.2f\n",x,y);swap(x,y);printf("調(diào)用后x=%.2f,y=%.2f\n",x,y);}【例8.3】數(shù)組名作為函數(shù)參數(shù)應(yīng)用舉例。程序源碼如下：#include<stdio.h>intarrx(int*n);voidmain(){inti;intm[10];for(i=0;i<10;i++)m[i]=i;arrx(m);}intarrx(int*n){intj;for(j=0;j<10;j++)printf("%3d",*(n++));printf("\n");}【例84】判斷下面程序中sum()函數(shù)的返回值類型。程序源碼如下：#include<stdio.h>sum(floatx,floaty){floats;s=x+y;return(s);}voidmain(){floata,b;ints;scanf("%f,%f",&a,&b);s=sum(a,b);printf("sum=%d\n",s);}【例8.5】func函數(shù)被調(diào)用，func函數(shù)不返回值，只完成某種操作。程序源碼如下：#include<stdio.h>func(){printf(”這是一個C函數(shù)調(diào)用！\n");}voidmain(){func();}【例8.6】調(diào)用求兩個實數(shù)的最大值函數(shù)fmax()，求三個數(shù)中的最大數(shù)。程序源碼如下：#include<stdio.h>floatfmax(floatx,floaty){floatm;m=x>y?x:y;return(m);}voidmain(){floata,b,c,result;scanf("%f,%f,%f",&a,&b,&c);result=fmax(fmax(a,b),c);printf("最大值result=%f\n",result);}【例8．7】編寫兩個函數(shù)，分別求兩個整數(shù)的最大公約數(shù)和最小公倍數(shù)，用主函數(shù)調(diào)用這兩個函數(shù)，并輸出結(jié)果。程序源碼如下：#include<stdio.h>intgcd(inta,intb) /*運(yùn)用輾轉(zhuǎn)相除法求最大公約數(shù)*/{intr,t;if(a<b){t=a;a=b;b=t;}r=a%b;while(r!=0){a=b;b=r;r=a%b;}return(b);}intlcm(inta,intb) /*求最小公倍數(shù)*/{intr;r=gcd(a,b);return(a*b/r);}voidmain(){intx,y;printf("請輸入兩個整數(shù)：\n");scanf("%d,%d",&x,&y);printf(”最大公約數(shù)=%d\n",gcd(x,y));/*調(diào)用gcd作為printf的參數(shù)表達(dá)式*/printf(”最小公倍數(shù)=%d\n",lcm(x,y));}【例88】用遞歸調(diào)用求n!,并輸出結(jié)果。程序源碼如下：#include<stdio.h>floatfac(intn) /*定義計算n!的函數(shù)*/{floatf;if(n<0)printf("n<0,dataerror!\n");elseif(n==0||n==1)f=1;elsef=n*fac(n-1);/*遞歸調(diào)用*/return(f);}voidmain(){intn；floaty；printf("請輸入一個整數(shù)：\n");scanf("%d",&n);y=fac(n);printf("%d!=%f\n",n,y);}【例8．9】Hanoi塔問題程序源碼如下：#include<stdio.h>voidmove(charone,chartwo){printf("%c--->%c\n",one,two);}voidhanoi(intn,charx,chary,charz){if(n==1)move(x,z);else{hanoi(n-1,x,z,y);move(x,z);hanoi(n-1,y,x,z);voidmain(){intm;printf("\nInputthenumberofdisks:");scanf("%d",&m);printf("Thestepstomoving%3ddiskesis:\n",m);hanoi(m,'A','B','C');}【例8．10】靜態(tài)局部變量的作用。程序源碼如下：voidmain(){inti;voidf(); /*函數(shù)說明*/for(i=1;i<=5;i++)f(); /*函數(shù)調(diào)用*/}voidf() /*函數(shù)定義*/{autointj=0;++j;printf("%d\n",j);}【例8．11】求2+4+6+??+200的和。程序源碼如下：voidmain(){registeri,s=0;for(i=2;i<=200;i+=2)s=s+i;printf("s=%d\n",s);}練習(xí)九例9．1】簡單的宏替換應(yīng)用實例，計算圓的周長、面積、體積程序源碼如下：#definePI3.1415926voidmain(){intr;floatl,s,v;printf("inputradius:");scanf("%d",&r);l=2.0*PI*r;s=PI*s=PI*r*r;v=4.0/3*PI*r*r*r;printf("l=%5.2f,s=%5.2f,v=%5.3f",l,s,v);}【例9．2】宏定義舉例。程序源碼如下：#defineJJVUjiujiangvocationaluniversityvoidmain(){printf("JJVU");}【例9．3】宏定義嵌套舉例。程序源碼如下：#defineA3.1415#defineBA*zvoidmain(){intz=4;printf("%5.2f",B);}【例9．4】宏定義舉例程序源碼如下：#definePprintf#defineB"%d"#defineF"%5.2f\n"voidmain(){inti=2,j=3;floatc=4.5,d=2.5;P(BF,i,c);P(BF,j,d);【例9．5】用有參數(shù)的宏定義輸出3個數(shù)中最小值，從而實現(xiàn)簡單的函數(shù)功能。程序源碼如下：#defineMIN(a,b)(a<b)?a:bvoidmain(){inti,j,z,min;printf("input3numbers:\n");scanf("%d%d%d",&i,&j,&z);min=MIN(i,j);min=MIN(z,min);printf("min=%d\n",min);}【例9．6】實參是表達(dá)式的宏定義程序。程序源碼如下：#defineH(a)(a)*(a+2)voidmain(){intb,i;printf("inputanumber:\n");scanf("%d",&b);i=H(b*2);printf("i=%d\n",i);}【例9．7】將上例中形參的括號去掉后的程序。程序源碼如下：#defineH(a)a*a+2voidmain(){intb,i;printf("inputanumber:\n");scanf("%d",&b);i=H(b*2);printf("i=%d\n",i);}【例9．8】帶參宏定義與函數(shù)調(diào)用的不同。程序源碼如下：#include"stdio.h"#defineP2(a)((a)*(a))P1(inta)return((a)*(a));}voidmain(){inti=5,j=5;while(i>=1)printf("%d\n",P1(i--));while(j>=1)printf("%d\n",P2(j--));}【例9．9】用宏定義來定義多個語句的輸出結(jié)果。程序源碼如下：#definePI3.1415926#defineH(a,b,c)a=PI*r*r;b=2*PI*r;c=4.0/3*PI*r*r*r;voidmain(){intr=4;floatl,m,n;H(l,m,n);printf("l=%f\nm=%f\nn=%f\n",l,m,n);}【例9．10】外部函數(shù)用文件包含實現(xiàn)。程序源碼如下：在文件f1.c中編寫如下：#include<stdio.h>#include"f2.c"voidvoidmain(){intn=10;printf("%ld",f(n));}在文件f2.c中編寫如下：longintf(intn){inti;longintp=1;for(i=1;i<=n;i++)p=p*i;return(p);}【例9．11】第一種條件編譯的應(yīng)用程序源碼如下：#include<stdio.h>#defineSUM1voidvoidmain(){inta=0;#ifdefSUMa=a+1;#elsea=a-1；#endifprintf("%d",a);}【例9．12】第二種條件編譯的應(yīng)用程序源碼如下：#include<stdio.h>#defineSUM1voidvoidmain(){inta=0;#ifndefSUMa=a+1;#elsea=a-1;#endifprintf("%d",a);}【例9．13】第三種條件編譯的應(yīng)用程序源碼如下：#include<stdio.h>#defineK1voidvoidmain(){floatc,s;printf("pleaseinputanumber:\n");scanf("%f",&c);#ifKs=2*3.1415*c;printf("zhouchangis:%f\n",s);#elses=3.1415*c*c;printf("mianjiis:%f\n",s);#endif}練習(xí)十【例10．1】在定義時對結(jié)構(gòu)體變量賦初值。程序源碼如下：#include<stdio.h>voidvoidmain(){structstudent{intnum;charname[10];charssex;floatlength;}a={102,"li",'B',167};printf("Num=%d\tName=%s\tSsex=%c\tLength=%5.2f\n",a.num,,a.ssex,a.length);}【例10．2】在定義后對結(jié)構(gòu)體變量賦初值。程序源碼如下：#include<stdio.h>#include<string.h>structstudent{intnum;charname[10];charssex;floatlength;}a;voidvoidmain(){a.num=102;printf("inputname:\n");gets();a.ssex='B';a.length=167;printf("Num=%d\tName=%s\tSsex=%c\tLength=%5.2f\n",a.num,,a.ssex,a.length);}【例10．3】計算學(xué)生的平均成績和及格的人數(shù)。要求：結(jié)構(gòu)體數(shù)組初始化方法采用定義結(jié)構(gòu)體數(shù)組時初始化。程序源碼如下：structstudent{intnumber;charname[10];charsex;floatscore;}stu[5]={{1,"ZhouPing",'M',40},{2,"Liluping",'M',60.5},{3,"ZhouYang",'G',76},{4,"ZhouYong",'M',21},{5,"CaoJing",'M',86},};voidmain(){inti,count=0;floata,sum=0;for(i=0;i<5;i++){sum+=stu[i].score;if(stu[i].score>60)count=count+1;}printf("s=%f\n",sum);a=sum/5;printf("average=%f\ncount=%d\n",a,count);}程序運(yùn)行結(jié)果如下：s=283.500000average=56.700001count=3【例10．4】計算學(xué)生的平均成績和及格的人數(shù)。要求：結(jié)構(gòu)體數(shù)組初始化方法采用定義結(jié)構(gòu)體數(shù)組之后初始化。程序源碼如下：#include<stdio.h>structstudentintnumber;charname[20];charsex;floatscore;};voidvoidmain(){structstudentstu[5]={{1,"ZhouPing",'M',40},{2,"Liluping",'M',60.5},{3,"ZhouYang",'G',76},{4,"ZhouYong",'M',21},{5,"CaoJing",'M',86},};inti,count=0;floata,sum=0;for(i=0;i<5;i++){sum+=stu[i].score;if(stu[i].score>60)count=count+1;}printf("s=%f\n",sum);a=sum/5;printf("average=%f\ncount=%d\n",a,count);}【例10．5】編寫一個函數(shù)，輸出結(jié)構(gòu)體變量各成員的值。程序源碼如下：#include<stdio.h>structstudent{intnumber;intcomputer,maths,english;ints;};voidp(structstudenta){printf("number=%d\tcomputer=%d\tmaths=%d\tenglish=%d\n",a.number,puter,a.maths,a.english);voidvoidmain(){structstudentb;b.number=6;puter=62;b.maths=79;b.english=90;p(b);}【例10．6】計算一個班(假設(shè)5名學(xué)生)中各學(xué)生的總成績程序源碼如下：#include<stdio.h>structstudent{intnumber;intcomputer,maths,english;ints;};voidsum(structstudentstu[],intn){inti;for(i=0;i<n;i++){stu[i].s=stu[i].computer+stu[i].maths+stu[i].english;}};voidvoidmain(){inti;structstudentb[5]={{1,60,70,40},{2,90,80,69},{3,84,64,76},{4,76,80,64},{5,76,64,86},};sum(b,5);for(i=0;i<5;i++){printf("%d\t%d\t\n",b[i].number,b[i].s);}【例10．7】定義一個簡單共用體，通過對其成員的多次賦值來研究成員值的變化情況。程序源碼如下：#include<stdio.h>unionsz{inta;floatb;};voidvoidmain(){unionszx;printf(“inputa:\n”);scanf(“%d”,&x.a);printf(“x.a=%d\n”,x.a);printf(“inputb:\n”);scanf(“%f”,&x.b);printf(“x.b=%f\n”,x.b);printf(“x.a=%d\n”,x.a);}【例10．8】輸出一張表格，內(nèi)有一個學(xué)校的若干人員信息，包括專職教師和行政人員的信息。程序源碼如下：#include<stdio.h>unionh{charzhicheng[10];intjibie;};structperson{intnum;charname[10];charjob;unionhzhiji;}person1[2];voidvoidmain(){intn,i;for(i=0;i<2;i++){scanf("%s%d%c",&person1[i].name,&person1[i].num,&person1[i].job);if(person1[i].job=='T')scanf("%s",&person1[i].zhiji.zhicheng);elsescanf("%d",&person1[i].zhiji.jibie);}printf("\nnum\tname\tjob\tjibie/zhicheng\n");for(i=0;i<2;i++)if(person1[i].job=='X')printf("%d\t%s\t%c\t%d\n",person1[i].num,person1[i].name,person1[i].job,person1[i].zhiji.jibie);elseif(person1[i].job=='T')printf("%d\t%s\t%c\t%s\n",person1[i].num,person1[i].name,person1[i].job,person1[i].zhiji.zhicheng);}【例10．9】輸入一個數(shù)，顯示相應(yīng)的月份。程序源碼如下：#include<stdio.h>voidmain(){inti,k;typedefenumyear{JAN=1,FEB,MAR,APR,AUG,SEP,OCT,NOV,DEC}A;Amonth[12],j;printf("\nPleaseInputTheMonth:");scanf("%d",&i);j=JAN;for(k=1;k<=12;k++){month[k]=j;j++;}switch(month[i]){caseJAN:printf("ThisisJANMonth.");break;caseFEB:printf("ThisisFEBMonth.");break;caseMAR:printf("ThisisMARMonth.");break;caseAPR:printf("ThisisAPRMonth.");break;caseAUG:printf("ThisisAUGMonth.");break;caseSEP:printf("ThisisSEPMonth.");break;caseOCT:printf("ThisisOCTMonth.");break;caseNOV:printf("ThisisNOVMonth.");break;caseDEC:printf("ThisisDECMonth.");break;default:printf("Inputerror!");break;}}練習(xí)十一【例11．1】取內(nèi)容運(yùn)算符的使用。程序源碼如下：voidmain(){inta,*p;p=&a;*p=100;printf("%d\n",a);a=200;printf("%d",*p);}【例11．2】改變指針變量的指向。程序源碼如下：voidmain(){inta=10,b=20,*p;p=&a;*p=15;printf("%d,%d\n",*p,a);p=&b;b=25;printf("%d,%d",*p,b);}【例11．3】比較指向數(shù)組的指針變量的大小。程序源碼如下：voidmain(){inta[8],*p1,*p2;p1=&a[1];p2=&a[4];if(p1==p2)printf("p1、p2指向同一元素");if(p1>p2)printf("p1處于高地址位置");if(p1<p2)printf("p1處于低地址位置");}【例11．4】兩個指針變量相減。程序源碼如下：voidmain(){inta[8],*p1,*p2;p1=&a[1];p2=&a[4];printf("%d",p2-p1);}【例11．5】采用指針法訪問數(shù)組元素。程序源碼如下：voidmain(){inta[5],*p1,i;p1=a;for(i=0;i<5;i++)*(p1+i)=i;for(i=0;i<5;i++)printf("a[%d]=%d\n",i,*(p1+i));}【例11．6】指向一維數(shù)組的指針變量指向二維數(shù)組。程序源碼如下：voidmain(){inta[3][4]={{0,1,2,3},{4,5,6,7},{8,9,10,11}},*p1,*p2;p1=&a[1][2];p2=p1+4;printf("%d,%d",*p1,*p2);}【例11．7】將二維數(shù)組中的元素輸出。程序源碼如下：voidmain(){inta[3][4]={0,1,2,3,4,5,6,7,8,9,10,11};int(*p)[4];inti,j;p=a;for(i=0;i<3;i++)for(j=0;j<4;j++)printf("%2d",*(*(p+i)+j));}【例11．8】指向字符串的指針變量。程序源碼如下：voidmain(){char*s="Iamastudent.";printf("%c,",s[2]);printf("%c",*(s+2));}【例11．9】指向字符串的指針變量。程序源碼如下：voidmain(){char*s="Iamastudent.";printf("%s\n",s);printf("%s\n",s+3);}【例11．10】程序源碼如下：voidfun(intnum){num=num*2;}voidmain(){inti=5;fun(i);printf("%d",i);}【例11．11】程序源碼如下：voidfun(int*num){*num=*num*2;}voidmain(){inti=5;fun(&i);printf("%d",i);}【例11．12】編寫程序求五門課程的平均成績程序源碼如下：floataverage(float*pscore){inti;floatav,s=0;for(i=0;i<5;i++){s=s+*pscore;pscore++;}av=s/5;returnav;}voidmain(){floatscore[5],ave;inti;printf("請輸入五個分?jǐn)?shù):”)；for(i=0;i<5;i++)scanf("%f",&score[i])；ave=average(score)；printf("平均分為:％.2f",ave);}【例11．13】求兩個數(shù)的最大值。程序源碼如下：int*max(inta,intb){if(a>b)return&a;elsereturn&b;}voidmain()intx,y,*m;printf(”請輸入兩個整數(shù):”)；scanf("%d%d",&x,&y);m=max(x,y)；printf(”最大值為:％d",*m);}【例11．14】求兩個數(shù)的最大值。程序源碼如下：intmax(inta,intb){if(a>b)returna;elsereturnb;}voidmain(){intx,y,m;int(*p)();p=max;printf(”請輸入兩個整數(shù):”)；scanf("%d%d",&x,&y);m=p(x,y);printf(”最大值為:％d",m);}【例11．15】找到年齡最小的學(xué)生，并輸出結(jié)果程序源碼如下：structstudent{char*name;intage;}stu[4]={"li",18,"wang",16,"zhang",19,"sun",17};voidmain(){structstudent*pstu,*min_age;inti;min_age=pstu=stu;for(i=0;i<4;i++){if(pstu->age<min_age->age)min_age=pstu;pstu++;}printf("年齡最小的是:％s，為％d歲",min_age->name,min_age->age);}【例11．16】從鍵盤輸入5個整數(shù)，統(tǒng)計其中奇數(shù)的個數(shù)。程序源碼如下：#include"malloc.h"voidmain(){int*p,i,odd=0;p=(int*)malloc(5*sizeof(int));printf(請輸入5個整數(shù):")；for(i=0;i<5;i++)scanf("%d",p+i)；for(i=0；i<5；i++)if(p[i]%2!=0)odd++；printf("其中有％小個奇數(shù)",odd);free(p)；}【例11．17】從鍵盤輸入一行字符，寫入一個文件，再把該文件的內(nèi)容讀出顯示在屏幕上。程序源碼如下：#include"stdio.h"#include"process.h"voidmain(){FILE*fp;charch;if((fp=fopen("c:\\sl.txt","wt+"))==NULL)/*建立文件*/{printf("\nerroronopenc:\\sl.txtfile!");exit(l);}printf("請輸