diff --git a/pairing.java b/pairing.java new file mode 100644 index 0000000..64de8c4 --- /dev/null +++ b/pairing.java @@ -0,0 +1,29 @@ +import java.io.*; + +class GFG { + + // Returns count of ways n people + // can remain single or paired up. + static int countFriendsPairings(int n) + { + int dp[] = new int[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 + public static void main(String[] args) + { + int n = 4; + System.out.println(countFriendsPairings(n)); + } +}