Add 4_Median_of_Two_Sorted_Arrays.java

Author: Sean Prashad

Modified Binary Search/4_Median_of_Two_Sorted_Arrays.java

@@ -0,0 +1,38 @@
+class Solution {
+    public double findMedianSortedArrays(int[] nums1, int[] nums2) {
+        int m = nums1.length;
+        int n = nums2.length;
+        int sum = m + n;
+        int target = sum / 2;
+
+        if (sum % 2 == 0) {
+            return ((double) findKth(nums1, nums2, 0, 0, target) + findKth(nums1, nums2, 0, 0, target + 1)) / 2;
+        } else {
+            return (double) findKth(nums1, nums2, 0, 0, target + 1);
+        }
+    }
+
+    private int findKth(int[] a, int[] b, int startA, int startB, int k) {
+        if (startA >= a.length) {
+            return b[startB + k - 1];
+        }
+        if (startB >= b.length) {
+            return a[startA + k - 1];
+        }
+        if (k == 1) {
+            return Math.min(a[startA], b[startB]);
+        }
+
+        int midAIdx = startA + k / 2 - 1;
+        int midBIdx = startB + k / 2 - 1;
+
+        int midA = (midAIdx >= a.length) ? Integer.MAX_VALUE : a[midAIdx];
+        int midB = (midBIdx >= b.length) ? Integer.MAX_VALUE : b[midBIdx];
+
+        if (midA > midB) {
+            return findKth(a, b, startA, startB + k / 2, k - k / 2);
+        } else {
+            return findKth(a, b, startA + k / 2, startB, k - k / 2);
+        }
+    }
+}