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  1. #include <iostream>
  2. #include <cmath>
  3. #include <vector>
  4.  
  5. using namespace std;
  6.  
  7. string s;
  8. int m;
  9.  
  10. bool solve(int n, int sum, string expr) {
  11.     if (n >= s.length()) {
  12.         if (sum == m) {
  13.             cout << m<< " = "<< expr << endl;
  14.             return true;
  15.         }
  16.         return false;
  17.     }
  18.  
  19.     if (solve(n + 1, sum + int(s[n]) - int('0'), expr + " + " + s[n]))
  20.         return true;
  21.  
  22.     if (solve(n + 1, sum - int(s[n]) + int('0'), expr + " - " + s[n]))
  23.         return true;
  24.  
  25.     return false;
  26. }
  27.  
  28. int main() {
  29.     cin >> m;
  30.     cin >> s;
  31.  
  32.     if (!solve(1, int(s[0]) - int('0'), string(1, s[0]))) {
  33.         cout << "Khong thayyy :(" << endl;
  34.     }
  35.  
  36.     return 0;
  37. }
  38.  
Success #stdin #stdout 0.01s 5280KB
comments (?)
stdin
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12
1234567
stdout
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12 = 1 + 2 - 3 + 4 - 5 + 6 + 7
https://ideone.com/MuNg0L
language:
C++ (gcc 8.3)
created:
1 day ago
visibility:
public

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