852.peak-index-in-a-mountain-array.java

/*
 * @lc app=leetcode id=852 lang=java
 *
 * [852] Peak Index in a Mountain Array
 */

// @lc code=start
class Solution {
    public int peakIndexInMountainArray(int[] A) {
        int low = 0;
        int high = A.length - 1;

        while (low < high) {
            int mid = low + (high - low) / 2;
            if (A[mid] < A[mid + 1]) {
                low = mid + 1;
            } else {
                high = mid;
            }
        }
        return low;
    }
}
// @lc code=end