leetcode

commit 970ec378e85247c562015ac6aae8854e397c0bfa
parent 58416348bdee3ab7c7a2afe94834bba24c5407ea
Author: AndrewLockVI <andrewlaack1@gmail.com>
Date:   Wed, 26 Apr 2023 17:24:38 -0500

Completed longest valid parentheses question in js

Diffstat:
A
longest-valid-parentheses/longest-valid-parentheses.js
 | 
53
+++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 53 insertions(+), 0 deletions(-)
diff --git a/longest-valid-parentheses/longest-valid-parentheses.js b/longest-valid-parentheses/longest-valid-parentheses.js
@@ -0,0 +1,53 @@
+//This is the brute force to a problem which is to find the longest set of valid parenthesis in a 
+//list of parenthesis. The time complexity of this code is O(n^2) where n is the length of the string.
+//This is because for every value you have to iterate through all others values in the worst case.
+//Time: 3027ms Beats: 5.3%
+//Memory: 82.5MB Beats: 5.3%
+
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var longestValidParentheses = function(s) {
+    let longest = 0;
+    for(let i = 0 ; i < s.length ; ++i){
+        let current_string = s.substring(i);
+        let check_val = check_valid(current_string);
+        if(check_val > longest){
+            longest = check_val; 
+        }
+    }
+    return longest;
+};
+
+function check_valid(s){
+    let max = 0;
+    let curr_max = 0;
+    let vals = [];
+    for(let i = 0 ; i < s.length ; ++i){
+        let curr = s[i];
+        if(curr == '[' || curr == '{' || curr == "("){
+            vals.push(curr);
+        }
+        else{
+            if (vals.length == 0) {
+                return max;
+            }
+            let popped = vals.pop();
+            if(
+                popped == '[' && curr != ']' ||
+                popped == '(' && curr != ')' ||
+                popped == '{' && curr != '}'
+                ){
+                    return max;
+                }
+            else{
+                curr_max += 2;
+            }
+        }
+        if(vals.length == 0){
+            max = curr_max;
+        }
+    }
+    return max;
+}