demo of DP to find fibonacci of num iteratively, O(N) time & less space than recursive one

Author: NirmalSilwal

CodingBlocks Training/Day27/fibonacciDPIterative.java

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+package Lecture27;
+
+//time complexity: O(n)
+// it has better space complexity than fibonacciDyanamicProg.java using recursive apporach, though time
+// complexity is same using DP approach.
+
+public class fibonacciDPIterative {
+
+	public static void main(String[] args) {
+
+		int nthItem = 5;
+		System.out.println(fibIterative(nthItem)); // 5
+
+		System.out.println(fibIterative(0)); // 0
+		System.out.println(fibIterative(1)); // 1
+		System.out.println(fibIterative(6)); // 8
+	}
+
+	public static int fibIterative(int n) {
+		int[] memStorage = new int[n + 1];
+		return fibIterative(n, memStorage);
+	}
+
+	private static int fibIterative(int n, int[] storage) {
+		if (n == 0 || n == 1) {
+			return n;
+		}
+
+		storage[0] = 0;
+		storage[1] = 1;
+
+		for (int i = 2; i <= n; i++) {
+			storage[i] = storage[i - 1] + storage[i - 2];
+		}
+
+		return storage[n];
+	}
+
+}