PAT 1023. Have Fun with Numbers (20)

Notice that the number 123456789 is a 9-digit number consisting exactly the numbers from 1 to 9, with no duplication. Double it we will obtain 246913578, which happens to be another 9-digit number consisting exactly the numbers from 1 to 9, only in a different permutation. Check to see the result if we double it again!

Now you are suppose to check if there are more numbers with this property. That is, double a given number with k digits, you are to tell if the resulting number consists of only a permutation of the digits in the original number.

Input Specification:

Each input file contains one test case. Each case contains one positive integer with no more than 20 digits.

Output Specification:

For each test case, first print in a line "Yes" if doubling the input number gives a number that consists of only a permutation of the digits in the original number, or "No" if not. Then in the next line, print the doubled number.

Sample Input:

1234567899

Sample Output:

Yes
2469135798

---

#include<stdio.h>
#include<string.h>
char s[22];
char s2[22];
int a[10];
int main()
{
        scanf("%s\n", s);
        int i;
        int j =0;
        int temp = 0;
        int carry = 0;
        for(i = strlen(s)-1;i >= 0; i--){
                temp = s[i] - '0';
                a[temp]++;
                temp = temp*2 + carry;
                s2[i] = temp%10 + '0';
                a[temp%10]--;
                carry = temp/10;
        }
        if(carry != 0 ) a[carry]--;
        int flag = 0;
        for(i = 0; i< 10; i++){
            if(a[i] != 0){
                flag = 1;
                  break;
             }
        }
        if(flag) printf("No\n");
        else printf("Yes\n");
        if(carry != 0 ) printf("%d",carry);
        for(i = 0 ; i < strlen(s2); i++){
                printf("%c",s2[i]);
        }
        printf("\n");
        return 0;
}