CodeForces 508C (贪心)
来源:互联网 发布:linux chmod-r 777 编辑:程序博客网 时间:2024/04/20 03:26
Description
Anya loves to watch horror movies. In the best traditions of horror, she will be visited by m ghosts tonight. Anya has lots of candles prepared for the visits, each candle can produce light for exactly t seconds. It takes the girl one second to light one candle. More formally, Anya can spend one second to light one candle, then this candle burns for exactly t seconds and then goes out and can no longer be used.
For each of the m ghosts Anya knows the time at which it comes: the i-th visit will happen wi seconds after midnight, all wi’s are distinct. Each visit lasts exactly one second.
What is the minimum number of candles Anya should use so that during each visit, at least r candles are burning? Anya can start to light a candle at any time that is integer number of seconds from midnight, possibly, at the time before midnight. That means, she can start to light a candle integer number of seconds before midnight or integer number of seconds after a midnight, or in other words in any integer moment of time.
Input
The first line contains three integers m, t, r (1 ≤ m, t, r ≤ 300), representing the number of ghosts to visit Anya, the duration of a candle’s burning and the minimum number of candles that should burn during each visit.
The next line contains m space-separated numbers wi (1 ≤ i ≤ m, 1 ≤ wi ≤ 300), the i-th of them repesents at what second after the midnight the i-th ghost will come. All wi’s are distinct, they follow in the strictly increasing order.
Output
If it is possible to make at least r candles burn during each visit, then print the minimum number of candles that Anya needs to light for that.
If that is impossible, print - 1.
Sample Input
Input
1 8 3
10
Output
3
Input
2 10 1
5 8
Output
1
Input
1 1 3
10
Output
-1
Hint
Anya can start lighting a candle in the same second with ghost visit. But this candle isn’t counted as burning at this visit.
It takes exactly one second to light up a candle and only after that second this candle is considered burning; it means that if Anya starts lighting candle at moment x, candle is buring from second x + 1 to second x + t inclusively.
In the first sample test three candles are enough. For example, Anya can start lighting them at the 3-rd, 5-th and 7-th seconds after the midnight.
In the second sample test one candle is enough. For example, Anya can start lighting it one second before the midnight.
In the third sample test the answer is - 1, since during each second at most one candle can burn but Anya needs three candles to light up the room at the moment when the ghost comes.
这个题我本来是不想这样写的,但是自己的想法总是WA,伤心死了,不想再看这个题了,大神链接
#include <cstdio>#include <cstring>#define M 1000#define LL long longint a[M], flag[M];bool vis[M];int main(){ int m, r, t, num; while(scanf("%d%d%d", &m, &t, &r) != EOF) { num = 0; for(int i=1; i<=m; i++) { scanf("%d", &a[i]); a[i] += 500; } memset(vis, false, sizeof(vis)); memset(flag, 0, sizeof(flag)); for(int i=1; i<=m; i++) { if(flag[a[i]] < r) { for(int j=a[i]-1; j>=a[i]-t; j--) { if(!vis[j]) { num++; vis[j] = true; for(int k=j+1; k<=j+t; k++) { flag[k]++; } } if(flag[a[i]] >= r) break; } } if(flag[a[i]] < r) { num = -1; break; } } printf("%d\n", num); } return 0;}
- CodeForces 508C (贪心)
- Codeforces 805C (贪心)
- CodeForces 478C (贪心)
- 【CodeForces】508C - Anya and Ghosts(贪心 & 模拟)
- codeforces - 508C - Anya and Ghosts(贪心)
- Codeforces 508C Anya and Ghosts【贪心】
- Codeforces 394C Dominoes(贪心)
- Codeforces 401C Team(贪心+暴力)
- CodeForces 416C Booking System(贪心)
- CodeForces 460C--- Present(二分+贪心)
- CodeForces 219C Color Stripe (贪心)
- codeforces 219C Color Stripe(贪心)
- CodeForces 545C Woodcutters (贪心)
- codeforces 600C. Make Palindrome(贪心)
- codeforces 416C Booking System (贪心)
- CodeForces 626 C. Block Towers(贪心)
- CodeForces 615 C. Running Track(贪心)
- Codeforces 545 C Woodcutters(贪心/DP)
- LightOJ 1104 Birthday Paradox (离散概率)
- 204.[LeetCode]count primes
- Maven指令跳过单元测试
- 某教育平台项目开发之--使用SSM框架开发过程遇到的问题总结
- 二叉查找树与平衡树简介
- CodeForces 508C (贪心)
- 《Effect C++》学习------条款04:确定对象被使用前以先被初始化
- 微信全网发布检测出现的问题
- 【VS开发】使用WinPcap编程(4)——把网络数据包存储到一个文件中
- 读《代码大全》第2版 第 8 章,防御式编程
- 《Effect C++》学习------条款05:了解C++默默编写并调用哪些函数
- fopen()函数的整理
- Unity 3D - Debug
- velocity相关文档