做题博客链接
https://blog.csdn.net/qq_43349112/article/details/108542248
题目链接
https://leetcode-cn.com/problems/trapping-rain-water/
描述
给定 n 个非负整数表示每个宽度为 1 的柱子的高度图,计算按此排列的柱子,下雨之后能接多少雨水。
提示:
n == height.length
0 <= n <= 3 * 104
0 <= height[i] <= 105
示例
示例 1:
输入:height = [0,1,0,2,1,0,1,3,2,1,2,1]
输出:6
解释:上面是由数组 [0,1,0,2,1,0,1,3,2,1,2,1] 表示的高度图,在这种情况下,可以接 6 个单位的雨水
(蓝色部分表示雨水)。
示例 2:
输入:height = [4,2,0,3,2,5]
输出:9
初始代码模板
class Solution {
public int trap(int[] height) {
}
}
代码
推荐题解,里面除了单调栈之外还有其他优秀的解答方法:
https://leetcode-cn.com/problems/trapping-rain-water/solution/xiang-xi-tong-su-de-si-lu-fen-xi-duo-jie-fa-by-w-8/
class Solution {
public int trap(int[] height) {
LinkedList<Integer> stack = new LinkedList<>();
int res = 0;
for (int i = 0; i < height.length; i ++) {
while (!stack.isEmpty() && height[stack.peek()] < height[i]) {
int h = height[stack.pop()];
if (stack.isEmpty()) {
continue;
}
h = Math.min(height[stack.peek()], height[i]) - h;
int w = i - stack.peek() - 1;
res += h * w;
}
stack.push(i);
}
return res;
}
}