数据结构与算法[LeetCode]—Container With Most Water

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.

using namespace std;


#if  0
/*
 *最直观的比较方式
 * 复杂度O(N^2)
 * 代码通不过
 *
 */
class Solution{
public:
     int maxArea(vector<int> &height){
        int n=height.size();
        int i=0;
        int c_max=0;
        while(i<n){
           for(int end=i+1;end<n;end++)
               c_max=max(c_max,(end-i)*min(height[end],height[i]));
        i++;
        }
        return c_max;
     }
};

#endif

/*
 *思路：虽然本题有两个变化量，距离和高度都在变，但是坐标i每次变化都是单位1。则只用顾虑高度变化。
 *      虽然没有遍历完所有矩形。但能保证当前遍历的矩形在当前间距长度下，矩形面积一定是该距离下最大的。
 *
 * */
class Solution{
public:
    int maxArea(vector<int> &height){
         int end=height.size()-1;
         int start=0;
         int c_max=0;
         while(start<end){
           c_max=max(c_max,(end-start)*min(height[end],height[start]));
           if(height[start]<=height[end])
                     start++;
            else end--;   
         }
         return c_max;
    }
};