Container With Most Water <leetcode>

Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Find two lines, which together with x-axis forms a container, such that the container contains the most water.

Note: You may not slant the container.

class Solution {
public:
    int maxArea(vector<int> &h) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int res=0;
        int n = h.size();
        int l=0,r=n-1;
        while(l<r)
        {
            res=max(res,min(h[l],h[r])*(r-l));
            if (h[l]<h[r])
            {
                int k=l;
                while(k<r&&h[k]<=h[l])
                    k++;
                l=k;
                }
            else
            {
                int k=r;
                while(k>l&&h[k]<=h[r])
                    k--;
                r=k;
             }
        }
        return res;
    }
};