LeetCode - 852. 山脉数组的峰顶索引

/**
 * @param {number[]} A
 * @return {number}
 */
var peakIndexInMountainArray = function(A) {
    let top = -1;
    for(let i = 1; i < A.length; i++){
        if(A[i] >= A[i-1]){
            continue;
        }else{
            top = i-1;
            break;
        }
    }
    return top;
};