Create 0901-online-stock-span.js

Added solution for online-stock-span in JS.

Author: aadil42

javascript/0901-online-stock-span.js

@@ -0,0 +1,36 @@
+//https://leetcode.com/problems/online-stock-span/
+class StockSpanner {
+    constructor() {
+      this.stack = [];
+    }
+    
+    // Time O(1) | Space O(1)
+    isEmpty() {
+      return this.stack.length === 0;
+    }
+    
+    // Time O(1) | Space O(1)
+    peek() {
+      return this.stack[this.stack.length - 1];
+    }
+    
+    // Time O(1) | Space O(1)
+    push(val) {
+      return this.stack.push(val);
+    }
+  
+    // Time O(1) | Space O(1)
+    pop() {
+      return this.stack.pop();
+    }
+  
+    // Time O(n) | Space O(1)
+    next(price) {
+      let currunt = 1;
+      while (this.peek() && this.peek()[0] <= price) {
+        currunt += this.pop()[1];
+      }
+      this.push([price, currunt]);
+      return this.peek()[1];
+    }
+  }