fork download
copy 
  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. int main(){
  5.     ios::sync_with_stdio(false);
  6.     cin.tie(nullptr);
  7.  
  8.     int n;
  9.     cin >> n;
  10.  
  11.     // Read the sequence of operations
  12.     vector<pair<char,int>> ops(n);
  13.     for(int i = 0; i < n; i++){
  14.         cin >> ops[i].first >> ops[i].second;
  15.     }
  16.  
  17.     // We'll build the three masks bit by bit.
  18.     int AND_mask = 1023;  // 10 bits of 1
  19.     int OR_mask  = 0;
  20.     int XOR_mask = 0;
  21.  
  22.     // For each bit position 0..9:
  23.     for(int bit = 0; bit < 10; bit++){
  24.         // Simulate starting from 0 and from 1.
  25.         int v0 = 0, v1 = 1;
  26.         for(auto &op : ops){
  27.             char c = op.first;
  28.             int x = (op.second >> bit) & 1; 
  29.             if(c == '&'){
  30.                 v0 &= x;
  31.                 v1 &= x;
  32.             } else if(c == '|'){
  33.                 v0 |= x;
  34.                 v1 |= x;
  35.             } else { // '^'
  36.                 v0 ^= x;
  37.                 v1 ^= x;
  38.             }
  39.         }
  40.         // Decide what our combined masks must do to reproduce (v0, v1):
  41.         if(v0 == 0 && v1 == 0){
  42.             // force 0: AND=0, OR=0, XOR=0
  43.             AND_mask &= ~(1<<bit);
  44.             // OR_mask bit stays 0
  45.             // XOR_mask bit stays 0
  46.         }
  47.         else if(v0 == 0 && v1 == 1){
  48.             // identity: AND=1, OR=0, XOR=0
  49.             // all masks already have these defaults
  50.         }
  51.         else if(v0 == 1 && v1 == 0){
  52.             // invert: AND=1, OR=0, XOR=1
  53.             XOR_mask |= (1<<bit);
  54.         }
  55.         else if(v0 == 1 && v1 == 1){
  56.             // force 1: AND=1, OR=1, XOR=0
  57.             OR_mask |= (1<<bit);
  58.         }
  59.     }
  60.  
  61.     // Collect the result operations
  62.     vector<pair<char,int>> result;
  63.     if(AND_mask != 1023) result.push_back({'&', AND_mask});
  64.     if(OR_mask  !=    0) result.push_back({'|', OR_mask});
  65.     if(XOR_mask !=    0) result.push_back({'^', XOR_mask});
  66.  
  67.     // Output
  68.     cout << result.size() << "\n";
  69.     for(auto &p : result){
  70.         cout << p.first << " " << p.second << "\n";
  71.     }
  72.  
  73.     return 0;
  74. }
  75.  
Success #stdin #stdout 0.01s 5316KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
0
https://ideone.com/LzvIT8
language:
C++ (gcc 8.3)
created:
7 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!