p2142 高精度减法c语言

以下是C语言实现高精度减法的示例代码：

#include <stdio.h>
#include <string.h>

#define MAX_LEN 1000

void subtract(char num1[], char num2[], char result[]) {
    int len1 = strlen(num1);
    int len2 = strlen(num2);
    int carry = 0;
    int i, j;

    // 从个位开始逐位相减
    for (i = len1 - 1, j = len2 - 1; i >= 0 || j >= 0; i--, j--) {
        int digit1 = (i >= 0) ? num1[i] - '0' : 0;
        int digit2 = (j >= 0) ? num2[j] - '0' : 0;
        int diff = digit1 - digit2 - carry;

        if (diff < 0) {
            diff += 10;
            carry = 1;
        } else {
            carry = 0;
        }

        result[i] = diff + '0';
    }

    result[len1] = '\0';
}

int main() {
    char num1[MAX_LEN];
    char num2[MAX_LEN];
    char result[MAX_LEN];

    printf("请输入被减数：");
    scanf("%s", num1);
    printf("请输入减数：");
    scanf("%s", num2);

    subtract(num1, num2, result);

    printf("减法结果：%s\n", result);

    return 0;
}