feat: 每日一题 - 2019-06-25

Author: luzhipeng

4.median-of-two-sorted-arrays.js

@@ -0,0 +1,33 @@
+/*
+ * @lc app=leetcode id=4 lang=javascript
+ *
+ * [4] Median of Two Sorted Arrays
+ */
+/**
+ * @param {number[]} nums1
+ * @param {number[]} nums2
+ * @return {number}
+ */
+function findKth(nums1, nums2, k) {
+  if (nums1.length === 0) return nums2[k - 1];
+  if (nums2.length === 0) return nums1[k - 1];
+  if (k == 1) return Math.min(nums1[0], nums2[0]);
+  let i = Math.min(k >> 1, nums1.length);
+  let j = Math.min(k >> 1, nums2.length);
+  if (nums1[i - 1] > nums2[j - 1]) {
+    return findKth(nums1, nums2.slice(j), k - j);
+  }
+
+  return findKth(nums1.slice(i), nums2, k - i);
+}
+var findMedianSortedArrays = function(nums1, nums2) {
+  // 1 
+  // 2 3 4 5
+  const m = nums1.length,
+    n = nums2.length;
+  return (
+    (findKth(nums1, nums2, (m + n + 1) >> 1) +
+      findKth(nums1, nums2, (m + n + 2) >> 1)) /
+    2.0
+  );
+};