是不应该用longlong吗 怎么解决呢

Question

这个为什么不可以呢 是用longlong有问题么 那么应该怎么写呢
希望各位指点

Answer 1

大整数加法了解一下

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

#define MAX_LEN 1024

char lhs[MAX_LEN];
char rhs[MAX_LEN];
char result[MAX_LEN];

int reverse(char *str);
void add(char *lhs, char *rhs, char *result);

int main()
{
    scanf("%s %s", lhs, rhs);
    add(lhs, rhs, result);
    printf("%s\n", result);
    return 0;
}

int reverse(char *str)
{
    const int len = (int)strlen(str);
    char temp;

    for (int i = 0; i != len / 2; i++)
    {
        temp = str[i];
        str[i] = str[len - i - 1];
        str[len - i - 1] = temp;
    }

    return len;
}

void add(char *lhs, char *rhs, char *result)
{
    int lhsLen = reverse(lhs);
    int rhsLen = reverse(rhs);

    int carry = 0;
    const int ten = 10;

    for (int i = 0, j = 0, sum; i < lhsLen || j < rhsLen; i++, j++)
    {
        sum = (i < lhsLen ? lhs[i] - '0' : 0) +
              (j < rhsLen ? rhs[j] - '0' : 0) + carry;

        result[i] = (char)(sum % ten + '0');

        carry = sum / ten;
    }

    int maxLen = lhsLen > rhsLen ? lhsLen : rhsLen;

    if (carry > 0)
    {
        result[maxLen++] = (char)(carry + '0');
    }

    result[maxLen] = '\0';

    reverse(result);
}