Merge pull request #136 from soumenmanik1911/patch-1

Efficiently find the median of two sorted arrays without fully merging them in java

Java/MedianOfTwoSortedArrays.java

@@ -0,0 +1,55 @@
+public class MedianOfTwoSortedArrays {
+
+    public static double findMedianSortedArrays(int[] nums1, int[] nums2) {
+        // Ensure nums1 is the smaller array
+        if (nums1.length > nums2.length) {
+            int[] temp = nums1;
+            nums1 = nums2;
+            nums2 = temp;
+        }
+
+        int x = nums1.length;
+        int y = nums2.length;
+        int low = 0, high = x;
+
+        while (low <= high) {
+            int partitionX = (low + high) / 2;
+            int partitionY = (x + y + 1) / 2 - partitionX;
+
+
+            int maxLeftX = (partitionX == 0) ? Integer.MIN_VALUE : nums1[partitionX - 1];
+            int minRightX = (partitionX == x) ? Integer.MAX_VALUE : nums1[partitionX];
+
+            int maxLeftY = (partitionY == 0) ? Integer.MIN_VALUE : nums2[partitionY - 1];
+            int minRightY = (partitionY == y) ? Integer.MAX_VALUE : nums2[partitionY];
+
+            if (maxLeftX <= minRightY && maxLeftY <= minRightX) {
+
+                if ((x + y) % 2 == 0) {
+                    return (Math.max(maxLeftX, maxLeftY) + Math.min(minRightX, minRightY)) / 2.0;
+                } else {
+                    return Math.max(maxLeftX, maxLeftY);
+                }
+            } else if (maxLeftX > minRightY) {
+
+                high = partitionX - 1;
+            } else {
+
+                low = partitionX + 1;
+            }
+        }
+
+
+        throw new IllegalArgumentException("Input arrays are not sorted");
+    }
+
+    public static void main(String[] args) {
+        int[] nums1 = {1, 3};
+        int[] nums2 = {2};
+        System.out.println("Median is: " + findMedianSortedArrays(nums1, nums2));  // Output: 2.0
+
+        int[] nums3 = {1, 2};
+        int[] nums4 = {3, 4};
+        System.out.println("Median is: " + findMedianSortedArrays(nums3, nums4));  // Output: 2.5
+    }
+}