题解 | #有效括号序列#

经典的用栈判断语法合法性问题

#include <stack>
#include <unordered_map>
class Solution {
  public:
    unordered_map<char, char> char_map = {{'(', ')'}, {'{', '}'}, {'[', ']'}};
    bool isValid(string s) {
        stack<char> stack;
        for (int i = 0; i < s.size(); i++) {
            if (!stack.empty() && char_map[stack.top()] == s[i]) {
                stack.pop();
            } else {
                stack.push(s[i]);
            }
        }
        return stack.empty();
    }
};