42. 接雨水

https://leetcode-cn.com/problems/trapping-rain-water/

 

 双指针解法。

 1 public class Solution
 2 {
 3     public int Trap(int[] height)
 4     {
 5         int size = height.Length, left = 0, right = size - 1, ans = 0, leftMax = 0, rightMax = 0;
 6         while (left < right)
 7         {
 8             if (height[left] < height[right])
 9             {
10                 if (height[left] >= leftMax)
11                 {
12                     leftMax = height[left];
13                 }
14                 else
15                 {
16                     ans += (leftMax - height[left]);
17                 }
18                 left++;
19             }
20             else
21             {
22                 if (height[right] >= rightMax)
23                 {
24                     rightMax = height[right];
25                 }
26                 else
27                 {
28                     ans += (rightMax - height[right]);
29                 }
30                 right--;
31             }
32         }
33         return ans;
34     }
35 }
View Code

 

posted @ 2020-03-31 18:42  Quintinz  阅读(170)  评论(0)  编辑  收藏  举报