LeetCode-11. 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 and n is at least 2.

The above vertical lines are represented by array [1,8,6,2,5,4,8,3,7]. In this case, the max area of water (blue section) the container can contain is 49.

Example:

Input: [1,8,6,2,5,4,8,3,7]
Output: 49

题解：

这种题一看O(n^2)肯定TLE

class Solution {
public:
  int maxArea(vector<int>& height) {
    int left = 0, right = height.size() - 1, ans = 0;
    while (left != right) {
      ans = max(ans, (right - left) * min(height[left], height[right]));
      if (height[left] > height[right]) {
        right--;
      }
      else {
        left++;
      }
    }
    return ans;
  }
};