leetcode 941. Valid Mountain Array

dont know why, but I prefer to use for instead of while.

class Solution {
    public boolean validMountainArray(int[] A) {
        if (A.length < 3) return false;
        int i = 0;
        for (; i < A.length - 1 && A[i] < A[i + 1]; ++i);
        if (i == 0 || i == A.length - 1) return false;
        for (; i < A.length - 1 && A[i] > A[i + 1]; ++i);
        if (i != A.length - 1) return false;
        return true;
    }
}