algorithm/Week_01/id_13/LeetCode_20_13.java at master · feixiangcode/algorithm · GitHub

27 lines (22 loc) · 683 Bytes

package leetCode;

import java.util.Stack;

public class LeetCode_20_13 {

public boolean isValid(String s) {

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

for (char ch : s.toCharArray()) {

if (stack.empty()) {

stack.push(ch);

} else if (isMatch(stack.peek(), ch)) {

stack.pop();

} else {

stack.push(ch);

}

return stack.empty();

}

private boolean isMatch(char ch1, char ch2) {

return ((ch1 == '{' && ch2 == '}')

|| ch1 == '[' && ch2 == ']'

|| ch1 == '(' && ch2 == ')');

}

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