FriendsPairing

dynamic_programming/friendspairing.cpp

@@ -0,0 +1,33 @@
+
+// C++ program solution friends pairing problem 
+// C++ program for solution of 
+// friends pairing problem 
+#include <bits/stdc++.h> 
+using namespace std; 
+
+// Returns count of ways n people  
+// can remain single or paired up. 
+int countFriendsPairings(int n) 
+{ 
+    int dp[n + 1]; 
+
+    // Filling dp[] in bottom-up manner using 
+    // recursive formula explained above. 
+    for (int i = 0; i <= n; i++) 
+    { 
+        if (i <= 2) 
+        dp[i] = i; 
+        else
+        dp[i] = dp[i - 1] + (i - 1) * dp[i - 2]; 
+    } 
+
+    return dp[n]; 
+} 
+
+// Driver code 
+int main() 
+{ 
+    int n = 4; 
+    cout << countFriendsPairings(n) << endl; 
+    return 0; 
+}