Give it an input and say what you think comes back. It compiles and runs for real, so a wrong guess still shows you the answer — probe as much as you like. Only correct predictions count.
Locked until you have predicted 4 outputs correctly.
| 1 | bool solution(const string& s) { |
| 2 | vector<char> pending; |
| 3 | for (char c : s) { |
| 4 | if (c == '(' || c == '[' || c == '{') { |
| 5 | pending.push_back(c); |
| 6 | continue; |
| 7 | } |
| 8 | if (pending.empty()) return false; |
| 9 | char top = pending.back(); |
| 10 | pending.pop_back(); |
| 11 | if (c == ')' && top != '(') return false; |
| 12 | if (c == ']' && top != '[') return false; |
| 13 | if (c == '}' && top != '{') return false; |
| 14 | } |
| 15 | return pending.empty(); |
| 16 | } |
Names have been stripped. The signature is the only clue you get for free. Compiled as C++20 with the standard headers and using namespace std; already in scope.