大整数比较大小

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=73

#include <stdio.h>
#include <string.h>
#define MAXN 1005

char a[MAXN],b[MAXN];
int len1,len2;

int main()
{
    while(scanf("%s%s",a,b))
    {
        if(a[0]=='0'&&b[0]=='0')
            break;
        int i;
        len1=strlen(a);
        len2=strlen(b);
        if(a[0]!='-'&&b[0]=='-')
            printf("a>b
");
        if(a[0]=='-'&&b[0]!='-')
            printf("a<b
");
        if(a[0]=='-'&&b[0]=='-')///同为负数
        {

            if(len1>len2)
                printf("a<b
");
            if(len1<len2)
                printf("a>b
");
            if(len1==len2)
            {
                for(i=0; i<len1; i++)
                {
                    if(a[i]>b[i])
                    {
                        printf("a<b
");
                        break;
                    }
                    if(a[i]<b[i])
                    {
                        printf("a>b
");
                        break;
                    }
                }
            }
            if(i==len1)
                printf("a==b
");
        }
        if(a[0]!='-'&&b[0]!='-')///同为正数
        {
            if(len1>len2)
                printf("a>b
");
            if(len1<len2)
                printf("a<b
");
            if(len1==len2)
            {
                for(i=0; i<len1; i++)
                {
                    if(a[i]>b[i])
                    {
                        printf("a>b
");
                        break;
                    }
                    if(a[i]<b[i])
                    {
                        printf("a<b
");
                        break;
                    }
                }
            }
            if(i==len1)
                printf("a==b
");
        }
    }
    return 0;
}