DP-I : Started!

Author: avinashbest

dynamicProgramming1/FibonacciNumber.java

@@ -0,0 +1,40 @@
+package dynamicProgramming1;
+
+import java.util.Arrays;
+import java.util.Scanner;
+
+public class FibonacciNumber {
+    /*
+     * Memoization = Applying Recursion + Storing somewhere
+     * */
+    private static int fibonacci(int n, int[] dp) {
+        if (n == 0 || n == 1)
+            return n;
+
+        int ans1, ans2;
+        if (dp[n - 1] == -1) {
+            ans1 = fibonacci(n - 1, dp);
+            dp[n - 1] = ans1;
+        } else {
+            ans1 = dp[n - 1];
+        }
+
+        if (dp[n - 2] == -1) {
+            ans2 = fibonacci(n - 2, dp);
+            dp[n - 2] = ans2;
+        } else {
+            ans2 = dp[n - 2];
+        }
+
+        return ans1 + ans2;
+    }
+
+    public static void main(String[] args) {
+        Scanner scan = new Scanner(System.in);
+        int n = scan.nextInt();
+        int[] dp = new int[n + 1];
+        Arrays.fill(dp, -1); // Filling arrays element with -1
+        int answer = fibonacci(n, dp);
+        System.out.println(answer);
+    }
+}