大数相加

xiaolong — Tue, 13 Sep 2011 11:49:00 GMT

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

char a[105],b[105];

char* add(char *a,char *b)
{
    int i,j,k = 0,tmp[105],l1 = strlen(a),l2 = strlen(b);
    for (i = l1-1,j = l2-1;i >= 0 && j >= 0;--i,--j)
        tmp[k++] = a[i]+b[j]-'0'-'0';
    for (;i >= 0;--i)
        tmp[k++] = a[i]-'0';
    for (;j >= 0;--j)
        tmp[k++] = b[j]-'0';
    tmp[k] = 0;
    for (i = 0;i < k;++i)
    {
        tmp[i+1] += tmp[i]/10;
        tmp[i] %= 10;
    }

    if (!tmp[k])
        --k;
    for (i = 0;i <= k;++i)
        a[i] = tmp[k-i] + '0';
    a[k+1] = '\0';
    return a;
}

int main()
{
    char *r;
    while (scanf("%s%s",a,b) != EOF)
    {
        r = add(a,b);
        printf("%s\n",r);
    }
    return 0;
}

xiaolong 2011-09-13 19:49 发表评论

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大数相加