高精度模板算法必備

1、注意：減法、除法要用到compare 函數(shù)乘法需要加法的部分，加法需要減法部分#include <iostream>#include <string>using namespace std;int compare(string str1, string str2)if(str1.size() > str2.size()return 1;else if(str1.size() < str2.size()return -1;elsereturn pare(str2); int main()char ch;string s1, s2, res;while(cin

2、>> ch) cin >> s1>> s2;switch(ch) 高精度加法高精度減法高精度乘法高精度除法,返回商高精度除法, 返回余數(shù)case '+': res = ADD_INT(s1, s2); break; /case '-': res = MINUS_INT(s1, s2); break; /case '*': res = MULTIPLY_INT(s1, s2); break; /case '/': res = DIV_INT(s1, s2); break; /case 'm

3、': res = MOD_INT(s1, s2); break; / default : break;cout << res<< endl;return(0);/ 高精度加法string ADD_INT(string str1, string str2)string MINUS_INT(string str1, string str2);int sign = 1;string str;if(str10 = '-') if(str20 = '-') sign = -1;str = ADD_INT(str1.erase(0, 1),

4、str2.erase(0, 1);else str = MINUS_INT(str2, str1.erase(0, 1);else if(str20 = '-')str = MINUS_INT(str1, str2.erase(0, 1);else string:size_type l1, l2;int i;l1 = str1.size(); l2 = str2.size();if(l1 < l2) for(i = 1; i <= (int)(l2 - l1); i+)str1 = "0" + str1;else for(i = 1; i <

5、;= (int)(l1 - l2); i+)str2 = "0" + str2;int int1 = 0, int2 = 0;for(i = str1.size() - 1; i >= 0; i-) int1 = (int(str1i) - 48 + int(str2i) - 48 + int2) %10;int2 = (int(str1i) - 48 + int(str2i) - 48 +int2) / 10;str = char(int1 + 48) + str;if(int2 != 0) str = char(int2 + 48) + str;/ 運算后處理符號

6、位if(sign = -1) && (str0 !='0')str = "-" + str;return str;/ 高精度減法string MINUS_INT(string str1, string str2)string MULTIPLY_INT(string str1, string str2);int i,sign = 1;string str;if(str20 = '-')str = ADD_INT(str1, str2.erase(0, 1);else int res = compare(str1, str2);i

7、f(res = 0) return "0"if(res < 0) sign = -1;string temp = str1;str1 = str2;str2 = temp;string:size_type tempint;tempint = str1.size() - str2.size();for(int i = str2.size() - 1; i >= 0; i-) if(str1i + tempint < str2i) str1i + tempint - 1 = char(int(str1i + tempint - 1) - 1);str = ch

8、ar(str1i + tempint - str2i + 58) + str;elsestr = char(str1i + tempint - str2i + 48) + str;for(i = tempint - 1; i >= 0; i-)str = str1i + str;/ 去除結果中多余的前導0str.erase(0, str.find_first_not_of('0');if(str.empty() str = "0"if(sign = -1) && (str0 !='0')str = "-&quo

9、t; + str;return str;/ 高精度乘法string MULTIPLY_INT(string str1, string str2)int sign = 1;string str;if(str10 = '-') sign *= -1;str1 = str1.erase(0, 1);if(str20 = '-') sign *= -1;str2 = str2.erase(0, 1);int i, j;string:size_type l1, l2;l1 = str1.size(); l2 = str2.size();for(i = l2 - 1; i

10、>= 0; i -) / 實現(xiàn)手工乘法string tempstr;int int1 = 0, int2 = 0, int3 = int(str2i) - 48;if(int3 != 0) for(j = 1; j <= (int)(l2 - 1 - i); j+)tempstr = "0" + tempstr;for(j = l1 - 1; j >= 0; j-) int1 = (int3 * (int(str1j) - 48) + int2) % 10;int2 = (int3 * (int(str1j) - 48) + int2) / 10;temp

11、str = char(int1 + 48) + tempstr;if(int2 != 0) tempstr = char(int2 + 48) + tempstr;str = ADD_INT(str, tempstr);/ 去除結果中的前導0str.erase(0, str.find_first_not_of('0');if(str.empty() str = "0"if(sign = -1) && (str0 !='0')str = "-" + str;return str;/ 高精度除法string D

12、IVIDE_INT(string str1, string str2, int flag)/flag = 1 時 , 返回商 ; flag = 0 時 , 返回余數(shù)string quotient, residue;int sign1 = 1, sign2 = 1, i;if(str2 = "0") /判斷除數(shù)是否為0quotient = "ERROR!"residue = "ERROR!"if(flag = 1) return quotient;else return residue;if(str1 = "0")

13、/判斷被除數(shù)是否為0quotient = "0"residue = "0"if(str10 = '-') str1 = str1.erase(0, 1);sign1 *= -1;sign2 = -1;if(str20 = '-') str2 = str2.erase(0, 1);sign1 *= -1;int res = compare(str1, str2);if(res < 0) quotient = "0"residue = str1;else if(res = 0) quotient =

14、"1"residue = "0"else string:size_type l1, l2;l1 = str1.size(); l2 = str2.size();string tempstr;tempstr.append(str1, 0, l2 - 1);/ 模擬手工除法for(i = l2 - 1; i < l1; i+) tempstr = tempstr + str1i;for(char ch = '9' ch >= '0' ch -) string str;str = str + ch;if(compar

15、e(MULTIPLY_INT(str2, str), tempstr) <= 0)quotient = quotient + ch;tempstr = MINUS_INT(tempstr, MULTIPLY_INT(str2, str);break;residue = tempstr;/ 去除結果中的前導0quotient.erase(0, quotient.find_first_not_of('0');if(quotient.empty() quotient = "0"if(sign1 = -1) && (quotient0 !='0')quotient = "-" + quotient;if(sign2 = -1) && (residue0 !='0')residue = &q