1023 Have Fun with Numbers (20 分)

1023 Have Fun with Numbers (20 分)

 

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 kdigits, you are to tell if the resulting number consists of only a permutation of the digits in the original number.

Input Specification:

Each input 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

直接用字符串读入更好处理。

#include <bits/stdc++.h>
using namespace std;
int vis[10];
string s;
bool flag = true;

int main(){
    cin >> s;
    for(int i = 0; i < s.length(); i++){
        int x = s[i] - '0';
        vis[x]++;
    }
    int ans = 0;
    for(int i = s.length()-1; i >= 0; i--){
        int x = s[i] - '0';
        int k = x*2 + ans;
        int an = k%10;
        s[i] = an + '0';
        if(vis[an] >= 1)
            vis[an]--;
        else{
            flag = false;
        }
        ans = k/10;
    }
    if(ans == 1)
        s = '1'+ s;
    if(flag)
        cout <<"Yes"<<endl;
    else
        cout <<"No"<<endl;
    cout <<s<<endl;
    return 0;
}