题目地址:
https://leetcode.com/problems/container-with-most-water/description/
题目描述:
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 and n is at least 2.
我的代码:
class Solution {
public:
int maxArea(vector<int>& height) {
int n=height.size();
int s=0,e=n-1;
int mx=0;
while(s!=e){
mx=max(mx,(e-s)*min(height[s],height[e]));
if(height[s]<height[e]) s--;
else e--;
}
return mx;
}
};
解题思路:
题目和代码都很简单,就是求 max{(j-i)\*min(ai,aj),0 = <i<j<n }
。稍微有点意思的是证明我们的遍历过程是对的。
其实我们的遍历是对j-i从大到小的遍历,而每次去除较小值,因为当较小值依然代表容器的一条边时,j-i变小必然导致结果变小,由此,即可知正确性。显然复杂度为O(n)。