Added a solution

varunu28 · varunu28 · commit a50dfb7e2806 · 2018-06-19T20:12:16.000-07:00
diff --git a/Easy/Peak Index in a Mountain Array.java b/Easy/Peak Index in a Mountain Array.java
@@ -0,0 +1,21 @@
+class Solution {
+	public int peakIndexInMountainArray(int[] A) {
+        return peakIndexInMountainArrayImpl(A, 0, A.length-1);
+    }
+	
+	private int peakIndexInMountainArrayImpl(int[] arr, int start, int end) {
+		if (start > end) return -1;
+		
+		int mid = (start + end)/2;
+		
+		if (arr[mid] > arr[mid-1] && arr[mid] > arr[mid+1]) {
+			return mid;
+		}
+		else if (arr[mid] < arr[mid-1]) {
+			return peakIndexInMountainArrayImpl(arr, start, mid-1);
+		}
+		else {
+			return peakIndexInMountainArrayImpl(arr, mid+1, end);
+		}
+	}
+}
