翻译
给定一个只包含'(', ')', '{', '}', '[' 和']'的字符串,判断这个输入的字符串是否是有效的。
括号必须在正确的形式下闭合,() 和()[]{} 是有效的,但是 (] 和([)] 则不是。
原文
Given a string containing just the characters '(', ')', '{', '}', '[' and ']',
determine if the input string is valid.
The brackets must close in the correct order,
() and ()[]{} are all valid but (] and ([)] are not.
代码
class Solution {
public:
bool isValid(string s) {
if(s.size() % 2 != 0) return 0;
stack
brackets; int i = 0; while(i < s.size()) { if(brackets.empty()) { brackets.push(s[i]); } else { if((brackets.top() == '(' && s[i] == ')') || (brackets.top() == '[' && s[i] == ']') || (brackets.top() == '{' && s[i] == '}')) { brackets.pop(); } else { brackets.push(s[i]); } } i ++; } return brackets.size() == 0; } };
?