1375. Bulb Switcher III

There is a room with n bulbs, numbered from 1 to n, arranged in a row from left to right. Initially, all the bulbs are turned off.

At moment k (for k from 0 to n - 1), we turn on the light[k] bulb. A bulb change color to blue only if it is on and all the previous bulbs (to the left) are turned on too.

Return the number of moments in which all turned on bulbs are blue.

Example 1:

Input: light = [2,1,3,5,4]
Output: 3
Explanation: All bulbs turned on, are blue at the moment 1, 2 and 4.

Example 2:

Input: light = [3,2,4,1,5]
Output: 2
Explanation: All bulbs turned on, are blue at the moment 3, and 4 (index-0).

Example 3:

Input: light = [4,1,2,3]
Output: 1
Explanation: All bulbs turned on, are blue at the moment 3 (index-0).
Bulb 4th changes to blue at the moment 3.

Example 4:

Input: light = [2,1,4,3,6,5]
Output: 3

Example 5:

Input: light = [1,2,3,4,5,6]
Output: 6

我可能是个傻批，花了好久才明白题意是什么
有n个灯，给一个数组代表在第i时刻light[i]打开灯，灯要变蓝必须满足自己和左边的灯都是开着，求一共多少个moments开着灯全是蓝色

class Solution {
    public int numTimesAllBlue(int[] light) {
        int res = 0, max = 0;
        for(int i = 0; i < light.length; i++){
            max = Math.max(max, light[i]);
            if(max == i + 1) res++;
        }
        return res;
    }
}

思路：