finds maximum sum of subarray of window size K, in O(N^2) Time, O(1) space

Author: NirmalSilwal

GeeksForGeeks/SlidingWindow/MaximumSubarraySum.java

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+package SlidingWindow;
+
+public class MaximumSubarraySum {
+
+	// brute force approch - O(N^2) Time | O(1) Space
+	public static int maxSubarraySum(int[] arr, int k) {
+
+		int maxsum = Integer.MIN_VALUE;
+
+		for (int i = 0; i <= arr.length - k; i++) {
+			int currsum = 0;
+
+			for (int window = 0; window < k; window++) {
+				currsum += arr[i + window];
+			}
+			maxsum = Math.max(maxsum, currsum);
+		}
+
+		return maxsum;
+	}
+
+	public static void main(String[] args) {
+		int[] arr = { 1, 4, 2, 10, 23, 3, 1, 0, 20 };
+		int windowSize = 4;
+		System.out.println(maxSubarraySum(arr, windowSize));
+	}
+}