Add kth order statistics

Sorting/kthOrderStatistic.cpp

@@ -0,0 +1,48 @@
+#include <bits/stdc++.h>
+using namespace std;
+int partition(vector<int> &v, int start, int end)
+{
+	if (start < end)
+	{
+		int i = start - 1, j, pi = v[end];
+		for (j = start; j < end; j++)
+		{
+			if (v[j] <= pi)
+			{
+				i++;
+				swap(v[i], v[j]);
+			}
+		}
+		swap(v[i + 1], v[end]);
+		return i + 1;
+	}
+	return -1;
+}
+int kthSmallest(vector<int> &v, int start, int end, int k)
+{
+	if (start > end)
+	{
+		return INT_MAX;
+	}
+	int pos = partition(v, start, end);
+	if(pos == -1)
+		return INT_MAX;	
+	if (pos - start == k - 1)
+	{
+		return v[pos];
+	}
+	else if (pos - start < k-1)
+		return kthSmallest(v, pos + 1, end, k-(pos-start+1));
+	return kthSmallest(v, start, pos - 1, k);
+}
+int main()
+{
+	vector<int> v{6, 5, 1, 0, 3, 2};
+	int ind = kthSmallest(v,0,5,4);
+	cout<<v[ind]<<"\n";
+	// sort(v.begin(),v.end());
+	// for(auto x:v)
+	// 	cout<<x<<" ";
+	// cout<<endl;
+	return 0;
+}