00-自测4. Have Fun with Numbers (20)

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;

int main()
{
    int a[20],b[20],i,len1,len2,flag,j,t,d;
    char s[25],s2[25];
    while(~scanf("%s",s))
    {
        memset(a,0,sizeof(a));
        memset(b,0,sizeof(b));
        memset(s2,0,sizeof(s2));
        len1=strlen(s);
        for(i=0; i<len1; i++)
            a[s[i]-48]++;
        d=0;
        j=0;
        for(i=len1-1;i>=0;i--)
        {
            t=s[i]-48;
            t=t*2+d;
            d=t/10;
            t%=10;
            s2[j++]=t+48;
        }
        len2=strlen(s2);
        if(d>0) {s2[j++]=d+48;len2++;}
        for(i=0; i<len2; i++)
            b[s2[i]-48]++;
        flag=1;
        for(i=0; i<=9; i++)
            if(a[i]!=b[i])
            {
                flag=0;
                break;
            }
        if(flag) printf("Yes\n");
        else printf("No\n");
        for(i=len2-1; i>=0; i--)
            printf("%c",s2[i]);
        printf("\n");
    }
    return 0;
}