pass problem 4 - median of two sorted arrays

Author: Bota5ky

binary_search/median_of_two_sorted_arrays/Solution.java

@@ -0,0 +1,37 @@
+package binary_search.median_of_two_sorted_arrays;
+
+/**
+ * @author Bota5ky
+ * @link <a href="https://leetcode.cn/problems/median-of-two-sorted-arrays/">4. 寻找两个正序数组的中位数</a>
+ * @since 2023-11-03 14:47
+ */
+class Solution {
+    public double findMedianSortedArrays(int[] nums1, int[] nums2) {
+        int len1 = nums1.length;
+        int len2 = nums2.length;
+        var odd = findKth(nums1, 0, len1 - 1, nums2, 0, len2 - 1, (len1 + len2 + 1) / 2);
+        var even = findKth(nums1, 0, len1 - 1, nums2, 0, len2 - 1, (len1 + len2 + 2) / 2);
+        return (odd + even) / 2.0;
+    }
+
+    private int findKth(int[] nums1, int start1, int end1, int[] nums2, int start2, int end2, int k) {
+        var len1 = end1 - start1 + 1;
+        var len2 = end2 - start2 + 1;
+        if (len1 > len2) {
+            return findKth(nums2, start2, end2, nums1, start1, end1, k);
+        }
+        if (len1 == 0) {
+            return nums2[start2 + k - 1];
+        }
+        if (k == 1) {
+            return Math.min(nums1[start1], nums2[start2]);
+        }
+        var i = start1 + Math.min(len1, k / 2) - 1;
+        var j = start2 + Math.min(len2, k / 2) - 1;
+        if (nums1[i] > nums2[j]) {
+            return findKth(nums1, start1, end1, nums2, j + 1, end2, k - (j + 1 - start2));
+        } else {
+            return findKth(nums1, i + 1, end1, nums2, start2, end2, k - (i + 1 - start1));
+        }
+    }
+}