用c语言实现高精度加减法

以下是用C语言实现高精度加减法的代码示例：

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

#define MAX_LEN 1000

void reverse(char *str) {
    int len = strlen(str);
    for (int i = 0; i < len / 2; i++) {
        char temp = str[i];
        str[i] = str[len - i - 1];
        str[len - i - 1] = temp;
    }
}

void add(char *a, char *b, char *result) {
    int len_a = strlen(a);
    int len_b = strlen(b);
    int carry = 0;
    int i = 0;
    while (i < len_a || i < len_b || carry != 0) {
        int x = i < len_a ? a[i] - '0' : 0;
        int y = i < len_b ? b[i] - '0' : 0;
        int sum = x + y + carry;
        result[i] = sum % 10 + '0';
        carry = sum / 10;
        i++;
    }
    result[i] = '\0';
    reverse(result);
}

void subtract(char *a, char *b, char *result) {
    int len_a = strlen(a);
    int len_b = strlen(b);
    int borrow = 0;
    int i = 0;
    while (i < len_a || i < len_b) {
        int x = i < len_a ? a[i] - '0' : 0;
        int y = i < len_b ? b[i] - '0' : 0;
        int diff = x - y - borrow;
        if (diff < 0) {
            diff += 10;
            borrow = 1;
        } else {
            borrow = 0;
        }
        result[i] = diff + '0';
        i++;
    }
    while (i > 1 && result[i - 1] == '0') {
        i--;
    }
    result[i] = '\0';
    reverse(result);
}

int main() {
    int n;
    scanf("%d", &n);
    while (n--) {
        char a[MAX_LEN], b[MAX_LEN], result[MAX_LEN];
        scanf("%s%s", a, b);
        add(a, b, result);
        printf("%s + %s = %s\n", a, b, result);
        subtract(a, b, result);
        printf("%s - %s = %s\n", a, b, result);
    }
    return 0;
}