[LeetCode] Container With Most Water

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.

 

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 Array Two Pointers

 

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    这题想明白题目之后不难，其实就是首尾指针向中间靠弄。

#include <iostream>
#include <vector>
using namespace std;

#define MIN(l,r) ((l)<(r)?(l):(r))
class Solution {
public:
    int maxArea(vector<int> &height) {
        int n = height.size();
        if(n<2) return 0;
        if(n==2)    return MIN(height[0],height[1]);
        int lidx=0,ridx=n-1,sum=0;
        while(lidx<ridx){
            if(sum<(ridx-lidx)*MIN(height[lidx],height[ridx]))
                sum = (ridx-lidx)*MIN(height[lidx],height[ridx]);
            if(height[lidx]<height[ridx])
                lidx++;
            else
                ridx--;
        }
        return sum;
    }
};

int main()
{
    vector<int > h{1,2,1};
    Solution sol;
    cout<<sol.maxArea(h)<<endl;
    return 0;
}