ADD: 162-Leetcode(Find Peak element)

JavaScript/findPeakElement.js

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+/**
+ * Given an integer array nums, find a peak element, and return its index. If the array contains multiple peaks, return the index to any of the peaks.
+
+Example 1:
+Input: nums = [1,2,3,1]
+Output: 2
+Explanation: 3 is a peak element and your function should return the index number 2.
+
+Example 2:
+Input: nums = [1,2,1,3,5,6,4]
+Output: 5
+Explanation: Your function can return either index number 1 where the peak element is 2, or index number 5 where the peak element is 6.
+
+ */
+
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var findPeakElement = function (nums) {
+  let left = 0,
+    right = nums.length - 1,
+    mid;
+
+  while (left < right) {
+    mid = Math.floor((right + left) / 2);
+    if (nums[mid] > nums[mid + 1]) right = mid;
+    else left = mid + 1;
+  }
+  return left;
+};