leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
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1106.cpp (1226B)

      1 class Solution {
      2   public:
      3     bool parseBoolExpr(const string &expression) const {
      4         bool state = false;
      5         stack<char> op;
      6 
      7         const auto flush = [&](int &i) {
      8             for (int count = 0; i < size(expression); i++) {
      9                 if (expression[i] == '(')
     10                     count++;
     11                 else if (expression[i] == ')' && count-- == 0)
     12                     break;
     13             }
     14             op.pop();
     15         };
     16 
     17         for (int i = 0; i < size(expression); i++) {
     18             switch (expression[i]) {
     19             case 't': state = true; break;
     20             case 'f': state = false; break;
     21             case '!':
     22             case '&':
     23             case '|': op.push(expression[i]); break;
     24             case ',':
     25                 // lazy evaluation
     26                 switch (op.top()) {
     27                 case '&':
     28                     if (!state) flush(i);
     29                     break;
     30                 case '|':
     31                     if (state) flush(i);
     32                     break;
     33                 }
     34                 break;
     35             case ')':
     36                 if (op.top() == '!') state = !state;
     37 
     38                 op.pop();
     39                 break;
     40             }
     41         }
     42 
     43         return state;
     44     }
     45 };