c語言初學必背代碼(共8頁)

1、/1.成績判斷#include int main()/成績int score;printf(請輸入你的成績:n);scanf(%d, &score);/判斷if(score =0 & score 60)printf(不及格n);else if(60 = score & score 80)printf(中等n);else if(80 = score & score 100)printf(優(yōu)秀n);elseprintf(輸入錯誤!n);/2.計算1到100的和#include int main()int sum = 0;/存結(jié)果變量int i;for(i=1;i = 100;i+)sum = su

2、m + i;printf(sum=%dn, sum);/3.最大公約數(shù)#include /求m,n的最大公約數(shù)int main()int m, n;int i, k;printf(請輸入兩個數(shù):);scanf(%d %d, &m, &n);/三元運算符找較小的那個k = m =1; i-)/這是公約數(shù)if(m % i = 0) & (n % i =0)printf(最大公約數(shù)是%dn, i);break;/跳出for循環(huán)/4.最小公倍數(shù)#include /求m,n的最小公倍數(shù)int main()int m, n;int max, min;/m,n中較大,較小的那個int k;/max, 2*m

3、ax, 3*max, .printf(請輸入兩個數(shù):);scanf(%d %d, &m, &n);/也可以交換m,n,保證m小n大max = m n ? m : n;min = m n ? m : n;k = max;/從max開始while(k % min != 0)k += max;/每次倍增printf(最小公倍數(shù)是%dn, k);/5.金字塔#include /金字塔int main()int i;/外層int j;/內(nèi)層for(i=1;i=10;i+)/當前是在第i行/先補空格10-i個for(j=1;j=10-i;j+)printf( );/再打2i-1個*for(j=1;j=2*

4、i-1;j+)printf(*);printf(n);/6.九九乘法表#include /打印九九乘法表int main()int i,j;for(i=1;i=9;i+)/外層一定是9行for(j=1; j=i; j+)/內(nèi)層第幾行走幾遍printf(%d*%d=%d , i, j, i*j);printf(n);/7.百錢買百雞#include /*百錢買百雞,類似1,2,5湊100銀幣問題*/int main2()int i,j;/公雞，母雞個數(shù)for(i=0; i=20; i+)/公雞for(j=0; j=33; j+)/母雞if( (15*i + 9*j + (100-i-j) = 3

5、00)printf(公雞%d，母雞%d，小雞%dn, i, j, 100-i-j);/1,2,5湊100銀幣問題int main3()int count = 0;/情況數(shù)int i,j;/5分個數(shù)，2分個數(shù)for(i=0; i=20; i+)/5分個數(shù)for(j=0; j=50; j+)/2分個數(shù)if( ( 5*i + 2*j ) = 100 ) count+;printf(%d: 5分%d個，2分%d個，1分%d個n, count, i, j, 100-5*i-2*j);/8.一維數(shù)組的最大值、最小值、平均值#include #define N 10/宏定義常量int main()int i

6、;/下標索引int max, min;double sum = 0;/累加和int aN = 58, 58, 96, 100, 25, 55, 66, 88, 99, 77;max = a0;/假設(shè)第一個最大min = a0;/假設(shè)第一個最小for(i=1; i max)/比最大值還大max = ai;/你才是最大if(ai min)/比最小值還小min = ai;/你才是最小sum += ai;printf(max=%d, min=%dn, max, min);printf(average = %.2lfn, sum/N);/9.二維數(shù)組的最大值、最小值、平均值#include int ma

7、in()int i; /第幾行int j; /第幾列int a34 = 1,2,3,4, 5,-6,7,8, 9,19,39,0;int max = a00;/假設(shè)你最大int min = a00;/假設(shè)你最小double average;/平均值double sum = 0; /總和for(i=0; i3; i+)/必定3行for(j=0; j max)max = aij;if(aij min)min = aij;printf(n);average = sum / (3*4);printf(max=%d, min=%d, avg=%.2lfn, max, min, average);/10.

8、二維數(shù)組轉(zhuǎn)置#include /二維數(shù)組轉(zhuǎn)置：行變列，列變行int main()int i; /第幾行int j; /第幾列int a34 = 1,2,3,4, 5,-6,7,8, 9,19,39,0;int b43;for(i=0; i3; i+)for(j=0; j4; j+)printf(%5d, aij);printf(n);/矩陣轉(zhuǎn)置for(i=0; i3; i+)for(j=0; j4; j+)bji = aij;for(i=0; i4; i+)for(j=0; j3; j+)printf(%5d, bij);printf(n);/11.冒泡排序#include #define N

9、 10/宏定義常量int main()int i;/下標索引int j;int tmp;/臨時交換用int aN = 58, 58, 96, 100, 25, 55, 66, 88, 99, 77;/外層循環(huán)一定是N-1for(i=0; iN-1; i+)/兩兩交換，大的往后走for(j=0; j aj+1)tmp = aj;aj = aj+1;aj+1 = tmp;for(i=0; iN; i+)printf(%d , ai);printf(n);/12.結(jié)構(gòu)冒泡排序#include /結(jié)構(gòu)定義,用戶自定義類型typedef struct studentchar sno20;/學號char

10、name20;/姓名int age;/年齡char gender;/性別char tel20;/電話;int main()int i;int j;double sum = 0;struct student tmp;/兩兩交換臨時用;/結(jié)構(gòu)數(shù)組struct student team5;for(i=0; i5; i+)printf(請輸入第%d個隊員的信息:n, i+1);scanf(%s %s %d %c %s, teami.sno, , &teami.age, &teami.gender, teami.tel);/按年齡冒泡排序for(i=0; i5; i+)for(j=0

11、; j teamj+1.age)tmp = teamj;teamj = teamj+1;teamj+1 = tmp;/取值printf(%-12s %-10s %-5s %-5s %-15sn, 學號, 姓名, 年齡, 性別, 電話);for(i=0; i5; i+)printf(%-12s %-10s %-5d %-5c %-15sn, teami.sno, , teami.age, teami.gender, teami.tel);/13.結(jié)構(gòu)數(shù)組找年齡最大值#include /結(jié)構(gòu)定義,用戶自定義類型typedef struct studentchar sno20;/

12、學號char name20;/姓名int age;/年齡char gender;/性別char tel20;/電話;int main()int i;struct student tmp;/找最大臨時用/結(jié)構(gòu)數(shù)組struct student team5;for(i=0; i5; i+)printf(請輸入第%d個隊員的信息:n, i+1);scanf(%s %s %d %c %s, teami.sno, , &teami.age, &teami.gender, teami.tel);/取值printf(%-12s %-10s %-5s %-5s %-15sn, 學號, 姓名,

13、 年齡, 性別, 電話);for(i=0; i5; i+)printf(%-12s %-10s %-5d %-5c %-15sn, teami.sno, , teami.age, teami.gender, teami.tel);/找學號最大的那一個tmp = team0;for(i=1; i 0 )tmp = teami;printf(學號最大的隊員如下:n);printf(%-12s %-10s %-5d %-5c %-15sn, tmp.sno, , tmp.age, tmp.gender, tmp.tel);/14.文件讀寫#include #inc

14、lude /結(jié)構(gòu)定義,用戶自定義類型typedef struct studentchar sno20;/學號char name20;/姓名int age;/年齡char gender;/性別char tel20;/電話;/文件讀寫int main()struct student * s, * p1;/個數(shù)未知FILE * fp;int i, n = 0;char buf1024;/fgets緩沖區(qū)/打開文件fp = fopen(e:test.txt, r);while(fgets(buf, 1024, fp) != NULL)n+;fclose(fp);/指向一個可以存儲n個student結(jié)構(gòu)

15、的內(nèi)存空間s = (struct student *)malloc(sizeof(struct student) * n);p1 = s;/不要動頭位置s的值/打開文件fp = fopen(e:test.txt, r);for(i=0; isno, p1-name, &p1-age, &p1-gender, p1-tel);p1+;fclose(fp);p1 = s;for(i=0; isno, p1-name, p1-age, p1-gender, p1-tel);free(s);/15.輸入三角形三邊長計算周長和面積#include #include int main() double a

16、rea,perimeter,s,a,b,c; printf(請輸入三邊長 a b c:); scanf(%lf%lf%lf,&a,&b,&c); if(a+bc) & (a+cb) & (b+ca) s=(a+b+c)/2; area=sqrt(s*(s-a)*(s-b)*(s-c); perimeter=a+b+c; printf(area=%.2f,perimeter=%.2fn,area,perimeter); else printf(三邊長無法構(gòu)成三角形。n); return 0; /16.輸入年份和月份輸出對應那一月的天數(shù)，要處理閏年#includeint main()int yea

17、r,month;int leap =0;scanf(%d %d,&year,&month);if(year %4=0 & year %100 !=0) | year %400 =0) /閏年2月29天leap=1;switch(month)case 1:case 3:case 5:case 7:case 8:case 10:case 12:printf(31);break;case 4:case 6:case 9:case 11:printf(30);break;case 2:printf(%d,28+leap);break;default:printf(error);break;return

18、 0;/17.1，2，5分硬幣問題#include int main()int sum = 0;for(int i=0; i=20; i+)/5分for(int j=0; j=50; j+)/2分if(5*i + 2*j = 100)sum+;elsebreak;printf(%dn, sum); /18.100到200所有的素數(shù)#include int main()int i,j,n;/外層for(i=100; i=200; i+)n = i;/內(nèi)層for(j=2;j=n-1;j+)if(n%j = 0)break;/不是素數(shù)if(j=n)/沒找到printf(%d是素數(shù)n, n);elseprintf(%d不是素數(shù)n, n);/19.輸入一個數(shù)n，計算12+22+32+n2#include int main()int sum = 0;int i,