25行代码C++ sort()函数解决

解题思路:

注意事项:

参考代码:

#include<iostream>

#include<algorithm>

#include<string>

using namespace std;

int main()

{

 int s,a=0;

 cin>>s;

 int m[4],flag=s;

 while (flag != 6174)

 {

  m[0] = flag / 1000;

  m[1] = (flag %1000)/100;

  m[2] = (flag % 100) / 10;

  m[3] = flag % 10;

  sort(m, m + 4);  int x = m[0] * 1000 + m[1] * 100 + m[2] * 10 + m[3];

  sort(m, m + 4, greater<int>()); int y = m[0] * 1000 + m[1] * 100 + m[2] * 10 + m[3]; 

  flag = y - x;

  a++;

 }

 cout << a++;

 return 0;

}