contains-duplicate solution

Author: krokerdile

contains-duplicate/krokerdile.js

@@ -0,0 +1,22 @@
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var containsDuplicate = function(nums) {
+    let dict = new Map();
+
+    nums.forEach((num)=>{
+        if(dict.has(num)){
+            dict.set(num, dict.get(num)+1);
+        }else{
+            dict.set(num, 1);
+        }
+    })
+
+    for (const num of nums) {
+        if(dict.get(num) >= 2){
+            return true;
+        }
+    }
+    return false;
+};