revision- finds maximum subarray sum, O(N) Time, O(1) space

Author: NirmalSilwal

Basic programs/revisited/MaximumSubarrayLC53.java

@@ -0,0 +1,30 @@
+package practice.revisited;
+
+// leetcode 53. Maximum Subarray
+public class MaximumSubarrayLC53 {
+
+	public static int maxSubArray(int[] nums) {
+
+		int maxsum = Integer.MIN_VALUE;
+		int currsum = 0;
+
+		for (int n : nums) {
+
+			currsum += n;
+			maxsum = Math.max(currsum, maxsum);
+
+			if (currsum < 0)
+				currsum = 0;
+		}
+
+		return maxsum;
+	}
+
+	public static void main(String[] args) {
+		int[] arr = { -2, 1, -3, 4, -1, 2, 1, -5, 4 };
+		System.out.println(maxSubArray(arr));
+
+		System.out.println(maxSubArray(new int[] { 1 }));
+		System.out.println(maxSubArray(new int[] { 5, 4, -1, 7, 8 }));
+	}
+}