g0001_0100.s0032_longest_valid_parentheses.Solution Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of leetcode-in-java17 Show documentation
Show all versions of leetcode-in-java17 Show documentation
Java Solution for LeetCode algorithm problems, continually updating
package g0001_0100.s0032_longest_valid_parentheses;
// #Hard #Top_100_Liked_Questions #String #Dynamic_Programming #Stack
public class Solution {
public int longestValidParentheses(String s) {
int max = 0;
int left = 0;
int right = 0;
int n = s.length();
char ch;
for (int i = 0; i < n; i++) {
ch = s.charAt(i);
if (ch == '(') {
left++;
} else {
right++;
}
if (right > left) {
left = 0;
right = 0;
}
if (left == right) {
max = Math.max(max, left + right);
}
}
left = 0;
right = 0;
for (int i = n - 1; i >= 0; i--) {
ch = s.charAt(i);
if (ch == '(') {
left++;
} else {
right++;
}
if (left > right) {
left = 0;
right = 0;
}
if (left == right) {
max = Math.max(max, left + right);
}
}
return max;
}
}