题解 | #括号序列#
括号序列
http://www.nowcoder.com/practice/37548e94a270412c8b9fb85643c8ccc2
import java.util.*; public class Solution { /** * * @param s string字符串 * @return bool布尔型 */ public boolean isValid (String s) { if (s == null || s.length() == 0) { return false; } Stack<Character> stack = new Stack<>(); char[] chars = s.toCharArray(); for (int i = 0; i < chars.length; i++) { if ('(' == chars[i]) { stack.push(')'); } else if ('[' == chars[i]) { stack.push(']'); } else if ('{' == chars[i]) { stack.push('}'); } else { if (stack.isEmpty() || stack.pop() != chars[i]) { return false; } } } //最后可能栈里还有元素 代表非合法括号序列 return stack.isEmpty(); } }
刷刷题 文章被收录于专栏
刷刷题 活跃活跃脑细胞