Create 0135-candy.js

Author: aadil42

javascript/0135-candy.js

@@ -0,0 +1,31 @@
+/**
+ * Array
+ * Time O(n) | Space O(n)
+ * https://leetcode.com/problems/candy/
+ * @param {number[]} ratings
+ * @return {number}
+ */
+var candy = function(ratings) {
+    
+    const ltr = new Array(ratings.length).fill(1);
+    const rtl = new Array(ratings.length).fill(1);
+
+    // go from left to right
+    for(let i = 1; i < ratings.length; i++) {
+      if(ratings[i] > ratings[i-1]) {
+        ltr[i] = ltr[i-1] + 1;
+      }
+    }
+    // go from right to left
+    for(let i = ratings.length - 2; i > -1; i--) {
+      if(ratings[i] > ratings[i+1]) {
+        rtl[i] = rtl[i+1] + 1;
+      }
+    }
+    // calc minimum 
+    let candy = 0;
+    for(let i = 0; i < ratings.length;  i++) {
+      candy += Math.max(ltr[i], rtl[i]);
+    }
+    return candy;
+};