题意:有\(n\)个桩子,\(1\)表示该位置有一个火炉,可以使两边距离为\(r\)的范围照亮,问最少使用多少炉子使得所有范围都被照亮. 题解:贪心,首先我们从\(r\)位置开始向左找,如果找到了就记录这个位置,然后答案+1,然后再从\(2*r-1\)这个位置开始向左找第一个没有标记的火炉,如果没有找到就直接输出\(-1\)结束,否则重复寻找的过程. 代码: int n,r; int a[N]; bool st[N]; int main() { ios::sync_with_stdio(fals…

任意门:http://codeforces.com/contest/1066/problem/B B. Heaters time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Vova's house is an array consisting of nn elements (yeah, this is the first probl…

http://codeforces.com/contest/1066/problem/B Vova's house is an array consisting of nn elements (yeah, this is the first problem, I think, where someone lives in the array). There are heaters in some positions of the array. The ii-th element of the a…

Codeforces Round #515 (Div. 3) #include<bits/stdc++.h> #include<iostream> #include<cstdio> #include<cstdlib> #include<cstring> #include<cmath> #include<algorithm> #include<queue> #include<vector> #incl…

题解:对于每个点 i 来说,从 j = i + r - 1 开始往前找,如果找到一个 a [ j ] 是 1 ,那么就把它选上,但是我们需要判断交界处,也就是如果前面选的那个可以让这个点变温暖,就不用再选多余的了.这样就记录一下前一个 last ,要满足 j > last.找到之后,就更新 i 的值,在 i + k 之间的都可以由选的这个点来温暖. #include <iostream> #include <bits/stdc++.h> using namespace std…

题目链接:http://codeforces.com/contest/1066 1066 A. Vova and Train 题意:Vova想坐火车从1点到L点,在路上v的整数倍的点上分布着灯笼,而在路上从l到r处停着别的火车,它挡着Vova的视线使他看不到灯笼.给定L,v,l,r求Vova能看到的灯笼数. 分析:从1到x上所有的灯笼数量为x/v个.则路上所有的灯笼数为L/v个,被挡住的则为 r/v - (l-1)/v 个,相减即为答案. #include<iostream> #include…

A. Mafia Time Limit: 20 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/348/problem/A Description One day n friends gathered together to play "Mafia". During each round of the game some player must be the supervisor and other n - 1…

B. Urbanization 题目链接 http://codeforces.com/contest/735/problem/B 题面 Local authorities have heard a lot about combinatorial abilities of Ostap Bender so they decided to ask his help in the question of urbanization. There are n people who plan to move…

题目链接: http://codeforces.com/problemset/problem/268/E E. Playlist time limit per test 1 secondmemory limit per test 256 megabytes 问题描述 Manao's friends often send him new songs. He never listens to them right away. Instead, he compiles them into a play…

B. Sail 题目连接: http://www.codeforces.com/contest/298/problem/B Description The polar bears are going fishing. They plan to sail from (sx, sy) to (ex, ey). However, the boat can only sail by wind. At each second, the wind blows in one of these directio…