LeeCode 11 double pointer

Title

Portal LeeCode 11

answer

The idea of ​​the double pointer is to reduce the scale of the problem. For the point with a small current boundary height, the optimal solution with this boundary as the boundary has been updated, so it can be removed to narrow the interval.

class Solution {
public:
    int maxArea(vector<int>& height) {
        int sz = height.size(), s = 0, t = sz - 1, res = 0;
        while(s < t){
            int m = min(height[s], height[t]);
            res = max(res, (t - s) * m);
            if(m == height[s]) ++s;
            else --t;
        }
        return res;
    }
};