39 lines
1.1 KiB
C
39 lines
1.1 KiB
C
|
#include <stdio.h>
|
||
|
|
#include <string.h>
|
||
|
|
#define MAX_LEN 1000
|
||
|
|
// 计算两个大整数的乘积
|
||
|
|
void multiply(const char* a, const char* b, char* result) {
|
||
|
|
int lenA = strlen(a), lenB = strlen(b), lenResult = lenA + lenB;
|
||
|
|
int arr[MAX_LEN * 2] = {0};
|
||
|
|
|
||
|
|
// 进行乘法运算
|
||
|
|
for (int i = 0; i < lenA; ++i)
|
||
|
|
for (int j = 0; j < lenB; ++j)
|
||
|
|
arr[i + j] += (a[lenA - i - 1] - '0') * (b[lenB - j - 1] - '0');
|
||
|
|
// 处理进位
|
||
|
|
for (int i = 0; i < lenResult - 1; ++i) {
|
||
|
|
arr[i + 1] += arr[i] / 10;
|
||
|
|
arr[i] %= 10;
|
||
|
|
}
|
||
|
|
// 构建结果字符串
|
||
|
|
int index = 0;
|
||
|
|
while (index < lenResult && arr[index] == 0) ++index;
|
||
|
|
if (index == lenResult) strcpy(result, "0");
|
||
|
|
else {
|
||
|
|
for (int i = index; i < lenResult; ++i)
|
||
|
|
result[i - index] = arr[lenResult - i - 1] + '0';
|
||
|
|
result[lenResult - index] = '\0';
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
int main() {
|
||
|
|
char a[MAX_LEN + 1], b[MAX_LEN + 1], result[MAX_LEN * 2 + 1];
|
||
|
|
printf("输入第一个大整数: ");
|
||
|
|
scanf("%s", a);
|
||
|
|
printf("输入第二个大整数: ");
|
||
|
|
scanf("%s", b);
|
||
|
|
multiply(a, b, result);
|
||
|
|
printf("结果: %s\n", result);
|
||
|
|
return 0;
|
||
|
|
}
|