Added cpp file of finding Kth Positive Integer

Author: Anish0203

C++/Algorithms/Searching-Algorithms/Find_kth_element.cpp

@@ -0,0 +1,46 @@
+/* Problem Statement
+Given an array arr of positive integers sorted in a strictly increasing order, and an integer k.
+Find the kth positive integer that is missing from this array
+Constraints:
+1 <= arr.length <= 1000
+1 <= arr[i] <= 1000
+1 <= k <= 1000
+arr[i] < arr[j] for 1 <= i < j <= arr.length
+*/
+#include<bits/stdc++.h>
+using namespace std;
+int findKthPositive(vector<int>& arr, int k)
+{
+ int b[10001];
+ int i; int ans = 0;
+ for (i = 0; i <= 10000; i++)
+ b[i] = i; //stores value i at every index i
+ for (i = 0; i < arr.size(); i++)
+ b[arr[i]] = -1; //stores -1 for elements already in the array
+
+ for (i = 1; i <= 10000; i++)
+ {
+ if (b[i] != -1) //if it is not -1, then it is counted towards kth integer, so k--
+ k--;
+ if (k == 0) // if k becomes 0, it means we have found kth positive integer
+ {
+ ans = i; //value is stored in ans
+ break;
+ }
+ }
+ return ans;
+}
+int main()
+{
+ vector<int> arr;
+ int n, k, i;
+ cin >> n >> k;
+ for (i = 0; i < n; i++) //takes input from user
+ {
+ int a;
+ cin >> a;
+ arr.push_back(a);
+ }
+ cout << findKthPositive(arr, k);
+ return 0;
+}