力扣第42题 接雨水

力扣第42题 接雨水

class Solution {
public:
    int trap(vector<int>& height) {
        int res = 0, left = 0, right = height.size() - 1;
        int left_max = 0, right_max = 0;
        while (left < right)
        {
            if (height[left] < height[right])
            {
                height[left] >= left_max ? left_max = height[left] : res += left_max - height[left];
                left++;
            }
            else
            {
                height[right] >= right_max ? right_max = height[right] : res += right_max - height[right];
                right--;
            }
        }
        return res;
    }
};