Container With Most Water

Q：

Given n non-negative integers a₁, a₂, ..., a_n, where each represents a point at coordinate (i, a_i). n vertical lines are drawn such that the two endpoints of line i is at (i, a_i) 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.

A:

先取两端，比它大的必定要么向左移一步，要么向右移一步，如果两端高度相等，左各移一步。

要想到的话还是有点困难。

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