题解 | #有效括号序列#

using System;
using System.Collections.Generic;


class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param s string字符串
     * @return bool布尔型
     */
    public bool isValid (string s) {
        // write code here
        if (string.IsNullOrWhiteSpace(s) || s.Length == 0)
            return true;
        List<char> listC = new List<char>() {
            s[0]
        };
        for (int nIndex = 1; nIndex < s.Length; nIndex++) {
            char c = s[nIndex];
            if (c == '(' || c == '[' || c == '{')
                listC.Add(c);
            else {
                if (listC.Count == 0)
                    return false;
                if ((listC[listC.Count - 1] == '(' && c == ')')
                        || (listC[listC.Count - 1] == '[' && c == ']')
                        || (listC[listC.Count - 1] == '{' && c == '}'))
                    listC.RemoveAt(listC.Count - 1);
                else
                    break;
            }
        }
        return listC.Count > 0 ? false : true;
    }
}