目录 题面 题目链接 题目描述 输入输出格式 输入格式 输出格式 输入输出样例 输入样例 输出样例 说明 思路 AC代码 题面 题目链接 P1948 [USACO08JAN]电话线Telephone Lines 题目描述 Farmer John wants to set up a telephone line at his farm. Unfortunately, the phone company is uncooperative, so he needs to pay for some of…

P1948 [USACO08JAN]电话线Telephone Lines 题目描述 Farmer John wants to set up a telephone line at his farm. Unfortunately, the phone company is uncooperative, so he needs to pay for some of the cables required to connect his farm to the phone system. There a…

P1948 [USACO08JAN]电话线Telephone Lines 题目描述 Farmer John wants to set up a telephone line at his farm. Unfortunately, the phone company is uncooperative, so he needs to pay for some of the cables required to connect his farm to the phone system. There a…

二分答案+单源最短路 POJ原题链接 洛谷原题链接 显然可以二分答案,检验\(mid\)可以使用最短路来解决. 将大于\(mid\)的边看成长度为\(1\)的边,说明要使用免费升级服务,否则长度为\(0\)边,即不需要占免费的资格. 然后就可以在上面跑最短路,如果\(dis[n]>k\)说明该答案不可行,将答案改大,否则说明可行,往小的去尝试. 而针对长度只有\(0,1\)的图可以使用双端队列的\(BFS\)来解决,不过我这种懒人就直接跑\(SPFA\)了. #include<cstdio&g…

题目描述 Farmer John wants to set up a telephone line at his farm. Unfortunately, the phone company is uncooperative, so he needs to pay for some of the cables required to connect his farm to the phone system. There are N (1 ≤ N ≤ 1,000) forlorn telephon…

这道题目有两种解法: 1.将每个点视为一个二元组(x,p),表示从起点到x有p条路径免费,相当于构建了一张分层图,N*k个节点,P*k条边.在这张图上用优先队列优化的SPFA算法求解,注意这里的d数组存的不是最短路径,而是路径中边权最大的值,最终答案就是min(d[n][j]),0<=j<=k . 1 #include<bits/stdc++.h> 2 using namespace std; 3 const int N=1005,M=20005; 4 int head[N],to…

[USACO08JAN]haybale猜测Haybale Guessing 题目描述 给一段长度为\(n\),每个位置上的数都不同的序列\(a[1\dots n]\)和\(q\)和问答,每个问答是\((x, y, r)\)代表\(\min_\limits{i=a}^ba_i= r\), 要你给出最早的有矛盾的那个问答的编号. 输入输出格式 输入格式: Line 1: Two space-separated integers: \(N\) and \(Q\) Lines 2..\(Q+1\): E…

P2899 [USACO08JAN]手机网络Cell Phone Network 题目描述 Farmer John has decided to give each of his cows a cell phone in hopes to encourage their social interaction. This, however, requires him to set up cell phone towers on his N (1 ≤ N ≤ 10,000) pastures (co…

传送门 这真是一道神仙题 虽然我猜到了这是一道LCA的题 但是... 第一遍看题,我是怎么也没想到能和树形图扯上关系 并且用上LCA 但其实其实和上一道lightoj上的那道题很类似 只不过那时一道很裸的板子 这个变了个形 但二分+LCA的思想是没有变的 ---------------------------------------------------------------------------- 为了方便描述,我们把左边的棋子称为a,中间的棋子称为b,右边的为c. 仔细观察跳棋规则,我…

题目描述 Farmer John has decided to give each of his cows a cell phone in hopes to encourage their social interaction. This, however, requires him to set up cell phone towers on his N (1 ≤ N ≤ 10,000) pastures (conveniently numbered 1..N) so they can all…