PAT 乙级 1019

题目

题目地址：PAT 乙级 1019

思路

本题没有考虑到小于1000的情况，当小于1000的时需要给vector的向量中推入0，直到向量中有四位数字，之后再进行排序并进行相关计算

代码

 #include <iostream>
 #include <algorithm>
 #include <vector>
 #include <cmath>
 using namespace std;

 bool compare(int a, int b) {
     return a > b;
 }

 int main() {
     vector<int> num;
     int n = ;
     cin >> n;
     while () {
         int chu = n, yu = ;
         while (chu >= ) {
             yu = chu % ;
             chu /= ;
             num.push_back(yu);
         }
         num.push_back(chu);
         if (num.size() < ) {
             for (int i = num.size(); i < ; i++)
                 num.push_back();
         }
         sort(num.begin(), num.end(), compare);
         int large = ;
         int jie = num.size() - ;
         for (int i = ; i < num.size(); i++) {
             large += num[i] * pow(, jie);
             jie--;
         }
         if (large < ) {
             if (large > )
                 cout << '';
             else if (large > )
                 cout << "";
             else
                 cout << "";
         }
         cout << large << " - ";
         sort(num.begin(), num.end());
         int little = ;
         jie = num.size() - ;
         for (int i = ; i < num.size(); i++) {
             little += num[i] * pow(, jie);
             jie--;
         }
         if (little < ) {
             if (little > )
                 cout << '';
             else if (little > )
                 cout << "";
             else
                 cout << "";
         }
         cout << little << " = ";
         if (large - little < ) {
             if (large - little > )
                 cout << '';
             else if (large - little > )
                 cout << "";
             else
                 cout << "";
         }
         cout << large - little << endl;
         if (large - little == )
             break;
         else if (large == little)
             break;
         else {
             n = large - little;
             num.clear();
         }
     }

     return ;
 }