【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

思考：使用两个指针left跟right，从数组头跟数组尾分别向中间逼近。

          储水量是由当前left跟right的距离与较低端的乘积

          当height[left] > height[right]时，right--。因为要保留最高高度，才有可能获取到更大的储水量max

          同理，当height[right] > height[left]时，left++;

具体代码如下：

class Solution {
    public int maxArea(int[] height) {
        if(height.length <= 1) {
            return 0;
        }
        int left = 0;
        int right = height.length - 1;
        int max = 0;
        while(left < right) {
            max = Math.max(max,Math.min(height[left],height[right]) * (right - left));
            if(height[right] > height[left]){
                left++;
            } else {
                right--;
            }            
        }
        return max;
    }
}