标签:
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.
用栈实现即可。
public class Solution {
public boolean isValid(String s) {
Stack<Character> stack = new Stack<>();
for (char c : s.toCharArray()) {
if (c == ‘)‘ || c == ‘}‘ || c== ‘]‘) {
if (stack.isEmpty()) {
return false;
} else {
char a = stack.pop();
if ((c == ‘)‘ && a != ‘(‘) || (c == ‘}‘ && a != ‘{‘) || (c == ‘]‘ && a != ‘[‘)) {
return false;
}
}
} else {
stack.push(c);
}
}
return stack.isEmpty();
}
}
标签:
原文地址:http://www.cnblogs.com/shini/p/4499291.html