LeetCode-Solutions-in-Cpp17

Solutions to high-frequency interview questions of LeetCode in C++17, taking into account both efficiency and comprehensibility.

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• 遍历字符串，如果是左括号则压到栈中，如果是右括号则检查是否与栈顶的左括号匹配，如果匹配则弹出栈顶元素。遍历完字符串，如果栈为空则说明所有括号均匹配成功

class Solution {
 public:
  bool isValid(string s) {
    stack<char> stk;
    for (auto& x : s) {
      if (x == '(' || x == '{' || x == '[') {
        stk.emplace(x);
      } else if (!empty(stk) && stk.top() == m.at(x)) {
        stk.pop();
      } else {
        return false;
      }
    }
    return empty(stk);
  }

 private:
  const unordered_map<char, char> m{
      {')', '('},
      {'}', '{'},
      {']', '['},
  };
};