added floyd cycle detection method

arrays/basics/findDuplicate.js

@@ -30,7 +30,44 @@ function findDuplicate2(nums){
  }
 }
 
-console.log("Actual: ",findDuplicate([1,3,4,2,2]), "Expected",2, findDuplicate([1,3,4,2,2]) == 2 ? "PASSED" : "FAILED", "\n")
+console.log("Actual: ",findDuplicate2([1,3,4,2,2]), "Expected",2, findDuplicate2([1,3,4,2,2]) == 2 ? "PASSED" : "FAILED", "\n")
+
+
+// 1 Using Object
+
+console.log("Approach 2")
+function findDuplicate3(nums){
+ let obj = {};
+ for(let item of nums){
+ if(obj[item]){
+ return item
+ }else{
+ obj[item] = 1
+ }
+ }
+}
 
+// console.log("Actual: ",findDuplicate3([1,3,4,2,2]), "Expected",2, findDuplicate3([1,3,4,2,2]) == 2 ? "PASSED" : "FAILED", "\n")
 
 
+function findDuplicate4(nums){
+ let slow = nums[0];
+ let fast = nums[0];
+
+ while(true){
+ slow = nums[slow];
+ fast = nums[nums[fast]]
+ if(slow == fast) break;
+ }
+ console.log(slow, fast)
+ slow = nums[0];
+ while(slow != fast){
+
+ slow = nums[slow]
+ fast = nums[fast]
+ }
+
+ return fast
+}
+
+console.log("Actual: ",findDuplicate4([2, 6, 4, 1, 3, 1, 5]), "Expected",1)