Merge pull request #2619 from aadil42/patch-62

javascript/0441-arranging-coins.js

@@ -0,0 +1,63 @@
+/**
+ * https://leetcode.com/problems/arranging-coins/
+ * Linear time
+ * Time O(n) | Space O(1)
+ * @param {number} n
+ * @return {number}
+ */
+var arrangeCoins = function(n) {
+
+    let steps = 1;
+    let canBuild = 0;
+
+    while(n >= steps) {
+        n = n - steps;
+        canBuild++;
+        steps++;
+    }
+
+    return canBuild || 1;
+};
+
+/**
+ * Binary Search
+ * Time O(log(n)) | Space O(1)
+ * @param {number} n
+ * @return {number}
+ */
+var arrangeCoins = function(n) {
+
+    let left = 1;
+    let right = n;
+    let result = 0;
+
+    while(left <= right) {
+
+        const mid = Math.floor((right+left)/2);
+        const total = (1 + mid) * (mid/2);
+        if(n < total) {
+            right = mid -1;
+        } else {
+            left = mid+1;
+            result = Math.max(result, mid);
+        }
+    }
+
+    return result;
+  };
+
+/** 
+ * Math 
+ * Time O(1) | Space O(1)
+ * @param {number} n
+ * @return {number}
+ */
+var arrangeCoins = function(n) {
+  let discriminant = 1 + 8 * n;
+  let sqrtDiscriminant = Math.sqrt(discriminant);
+
+  let result1 = Math.floor((-1 + sqrtDiscriminant) / 2);
+  let result2 = Math.floor((-1 - sqrtDiscriminant) / 2);
+
+  return Math.max(result1, result2);
+};