Merge pull request #70 from mephi007/master

Maximum circular subarray sum Issue #65, tested OK

Array/Max_sum_circular_array.java

@@ -0,0 +1,42 @@
+package hacktober;
+
+import java.util.Arrays;
+import java.util.Scanner;
+
+public class Max_sum_circular_array {
+
+	public static void main(String[] args) {
+		// TODO Auto-generated method stub
+		Scanner sc = new Scanner(System.in);
+		System.out.println("Enter number of element to be in array");
+		int n = sc.nextInt();
+		int[] arr = new int[n];
+		System.out.println("Enter elements to the array");
+		for (int i = 0; i < n; i++) {
+			arr[i] = sc.nextInt();
+		}
+
+		System.out.println(maxSumCircular(arr));
+	}
+		private static int maxSumCircular(int[] A) {
+			// TODO Auto-generated method stub
+			int curMax = 0;
+			int max = Integer.MIN_VALUE;
+			int curMin = 0;
+			int min = Integer.MAX_VALUE;
+			int sum = 0;
+			for (int i : A) {
+				sum += i;
+				curMin = Math.min(curMin + i, i);
+				min = Math.min(curMin, min);
+				curMax = Math.max(curMax + i, i);
+				max = Math.max(curMax, max);
+			}
+			if (sum == min) {
+				return max;
+			}
+			return Math.max(max, sum - min);
+
+		}
+
+}

Array/Rotate_an_array_to_the_left_by_3_position.java

@@ -0,0 +1,48 @@
+package Array;
+
+import java.util.Arrays;
+import java.util.Scanner;
+
+public class Rotate_an_array_to_the_left_by_3_position {
+
+	public static void main(String[] args) {
+		Scanner sc = new Scanner(System.in);
+		System.out.println("Enter number of element to be in array");
+		int n = 0;
+		do {
+			 n = sc.nextInt();
+			 if(n < 3) {
+				 System.out.println("Please enter number of element to be greater than 3");
+
+			 }
+		}while(n<3);
+
+		int[] arr = new int[n];
+		System.out.println("Enter elements to the array");
+		for (int i = 0; i < n; i++) {
+			arr[i] = sc.nextInt();
+		}
+
+		rotateby3(arr,3);
+		System.out.println(Arrays.toString(arr));
+	}
+
+	public static void rotateby3(int[] arr, int k) {
+		int n = arr.length;
+		rotate(arr,0,k-1);
+		rotate(arr,k,n-1);
+		rotate(arr,0,n-1);
+
+	}
+
+	public static void rotate(int[] arr, int start, int end) {
+		while(start <= end) {
+			int temp = arr[start];
+			arr[start] = arr[end];
+			arr[end] = temp;
+			start++;
+			end--;
+		}
+	}
+
+}