algorithm/Week_01/id_129/LeetCode_20_129.java at master · feixiangcode/algorithm · GitHub

30 lines (28 loc) · 876 Bytes

import java.util.Stack;

public class LeetCode_20_129 {

public static boolean isValid(String s) {

char[] chars = s.toCharArray();

Stack<Character> stack = new Stack<>();

for (char c : chars) {

if ('(' == c || '[' == c || '{' == c) {

stack.push(c);

} else if (')' == c || ']' == c || '}' == c) {

if (stack.empty()) {

return false;

}

char e = stack.pop();

if (!isSame(e, c)) {

return false;

}

if (stack.empty()) {

return true;

} else {

return false;

}

private static boolean isSame(char c1, char c2) {

return (c1 == '(' && c2 == ')') || (c1 == '[' && c2 == ']') || (c1 == '{' && c2 == '}');

}

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