@@ -0,0 +1,41 @@
+class solution
+{
+public:
+int *findTwoElement(int *arr, int n) {
+int *res= new int(2);
+int freq[n+1]={0};
+for (int i=0;i<n;i++)
+{
+freq[arr[i]]++; // go to that particular index and increment it by 1
+}
+for (int i=0;i<n;i++)
+{
+if (freq[arr[i]]>1) // if the index is greater then 1 that means it is a duplicate element
+res[0]=arr[i];
+if (freq[i]==0) // the index which will be having 0 will be the missing number
+res[1]=i;
+}
+// this is edge case when result's 1st index will be zero i.e last number is missing
+/* For example
+Possibly your code doesn't work correctly for multiple test-cases (TCs).
+
+The first test case where your code failed:
+
+Input:
+14
+12 7 5 1 13 1 10 8 11 9 2 4 3 6
+
+Its Correct output is:
+1 14
+
+And Your Code's output is:
+1 0
+*/
+if (res[1]==0)
+res[1]=n;
+return res;
+}
+};
+
+// O(2n)tc
+// o(n)sc