HDU 1506 Largest Rectangle in a Histogram(单调栈)
2021/6/5 10:20:55
本文主要是介绍HDU 1506 Largest Rectangle in a Histogram(单调栈),对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 20760 Accepted Submission(s):
6325
Usually, histograms are used to represent discrete distributions, e.g., the frequencies of characters in texts. Note that the order of the rectangles, i.e., their heights, is important. Calculate the area of the largest rectangle in a histogram that is aligned at the common base line, too. The figure on the right shows the largest aligned rectangle for the depicted histogram.
Input The input contains several test cases. Each test case describes a histogram and starts with an integer n, denoting the number of rectangles it is composed of. You may assume that 1 <= n <= 100000. Then follow n integers h1, ..., hn, where 0 <= hi <= 1000000000. These numbers denote the heights of the rectangles of the histogram in left-to-right order. The width of each rectangle is 1. A zero follows the input for the last test case.
Output For each test case output on a single line the area of the largest rectangle in the specified histogram. Remember that this rectangle must be aligned at the common base line.
Sample Input 7 2 1 4 5 1 3 3 4 1000 1000 1000 1000 0
Sample Output 8 4000
Source University of Ulm Local Contest 2003
Recommend LL | We have carefully selected several similar problems for you: 1505 1069 1087 1058 1176 一道挺裸的单调栈 我们预处理出每一个位置向左/向右第一个比他小的位置 然后统计答案,这样很显然是对的 时间复杂度$O(N)$
#include<cstdio> #define LL long long #define max(a,b) (a>b?a:b) #define min(a,b) (a<b?a:b) using namespace std; const int MAXN = 100001; LL a[MAXN]; int s[MAXN], top = 0; int L[MAXN], R[MAXN]; void clear() {top = 0;} int main() { //#ifdef WIN32 //freopen("a.in", "r", stdin); //#endif int N; while(~scanf("%d", &N) && N != 0) { clear(); s[0] = 0; for(int i = 1; i <= N; i++) scanf("%I64d",&a[i]); for(int i = 1; i <= N; i++) { while(top > 0 && a[i] <= a[ s[top] ]) top--; L[i] = min(s[top] + 1, i); s[++top] = i; } clear(); s[0] = N + 1; for(int i = N; i >= 1; i--) { while(top > 0 && a[i] <= a[ s[top] ]) top--; R[i] = max(s[top] - 1, i); s[++top] = i; } LL Ans = 0; for(int i = 1; i <= N; i++) Ans = max(Ans, (R[i] - L[i] + 1) * a[i] ); printf("%I64d\n",Ans); } return 0; }
这篇关于HDU 1506 Largest Rectangle in a Histogram(单调栈)的文章就介绍到这儿,希望我们推荐的文章对大家有所帮助,也希望大家多多支持为之网!
- 2024-09-28pyqt 怎么打包整个项目-icode9专业技术文章分享
- 2024-09-28laravel Commands 创建带有参数的 Artisan 命令的步骤和示例-icode9专业技术文章分享
- 2024-09-28antd怎么实现渲染tiff图片-icode9专业技术文章分享
- 2024-09-28英文半角中划线和中文全角的中划线有什么区别-icode9专业技术文章分享
- 2024-09-28nvm npm 和node 他们之间有什么关系-icode9专业技术文章分享
- 2024-09-28Node Version Manager (nvm)使用教程-icode9专业技术文章分享
- 2024-09-28nvm命令太慢,是什么原因-icode9专业技术文章分享
- 2024-09-28Kotlin 如何增加、删除和修改 MutableStateFlow 中的值。-icode9专业技术文章分享
- 2024-09-28Kotlin的stateFlow.update 写法介绍-icode9专业技术文章分享
- 2024-09-28kotlin 怎么获取当前时间格式-icode9专业技术文章分享