题意: 有向图,可以把k条路的长度变为0,求1到n的最短路 思路: 将图复制k份,一共k+1层图,对于每一条i→j,都连一条低层的i→高层的j,并且权值为0 即对每一对<i,j,w>,都加边<i,j,w>,<i+n,j+n,w>,<i+2n,j+2n,w>,....,<i+kn,j+kn,w> 同时加“楼梯”<i,j+n,0>,<i+n,j+2n,0>,...,<i+(k-1)n, j+kn> 然后跑一个1~(…
大致题意: 给定一个n个点m条边的图,在可以把路径上至多k条边的权值变为0的情况下,求S到T的最短路. 数据规模: N≤100000,M≤200000,K≤10 建一个立体的图,有k层,每一层是一份原图,消耗一次把一条边权值变为0的机会 = 在立体图中升一层 然后跑堆优化dij就好了,会卡spfa. AC代码: #include<cstdio> #include<queue> #include<cstring> #define rep(i,a,b) for(int i=…
There are N cities in the country, and M directional roads from u to v(1≤u,v≤n). Every road has a distance ci. Haze is a Magical Girl that lives in City 1, she can choose no more than K roads and make their distances become 0. Now she wants to go to…
传送门:https://nanti.jisuanke.com/t/A1958 题意:n个点m条边的路,你有k次机会将某条路上的边权变为0,问你最短路径长度 题解:最短路变形,我们需要在常规的最短路上多开 一维,记录,我消耗j次机会时的最短路径长度为多少 代码: /** * ┏┓ ┏┓ * ┏┛┗━━━━━━━┛┗━━━┓ * ┃ ┃ * ┃ ━ ┃ * ┃ > < ┃ * ┃ ┃ * ┃... ⌒ ... ┃ * ┃ ┃ * ┗━┓ ┏━┛ * ┃ ┃ Code is far away fro…
题意:N个点,M条带权有向边,求可以免费K条边权值的情况下,从点1到点N的最短路. 分析:K<=10,用dist[i][j]表示从源点出发到点i,免费j条边的最小花费.在迪杰斯特拉的dfs过程中,每个结点表示的状态有三个属性:访问至的结点,免费的边数和最小花费.将免费的边数看作层,则该图被分为k层.每次更新除了要对边进行松弛操作,也要对层之间进行松弛操作. #include<bits/stdc++.h> using namespace std; typedef long long LL;…
2018ICPC南京网络赛 A. An Olympian Math Problem 题目描述:求\(\sum_{i=1}^{n} i\times i! \%n\) solution \[(n-1) \times (n-1)! \% n= (n-2)!(n^2-2n+1) \%n =(n-2)!\] \[(n-2+1)\times (n-2)! \% n= (n-3)!(n^2-3n+2) \%n =(n-3)! \times 2\] 以此类推,最终只剩下\(n-1\) 时间复杂度:\(O(1)\…
There are NN cities in the country, and MMdirectional roads from uu to v(1\le u, v\le n)v(1≤u,v≤n). Every road has a distance c_ici​. Haze is a Magical Girl that lives in City 11, she can choose no more than KK roads and make their distances become 0…
题目链接:https://nanti.jisuanke.com/t/31001 题意: 一带权有向图,有 n 个节点编号1~n,m条有向边,现在一人从节点 1 出发,他有最多 k 次机会施展魔法使得某一条边的权变成 0,问他走到节点 n 的最小权值为多少. 题解: 将dist数组和vis数组都扩展一维: dist[c][i]代表:已经使用了 c 次变0魔法后,走到节点 i 的最短距离: vis[c][i]代表:已经使用了 c 次变0魔法后,走到节点 i 的最短距离,这个最短距离是否已经被准确计算…
题目链接:https://nanti.jisuanke.com/t/31001 解题心得: 一个BZOJ的原题,之前就写过博客了. 原题地址:https://www.lydsy.com/JudgeOnline/problem.php?id=2763 原题博客:https://www.cnblogs.com/GoldenFingers/p/9574230.html 比赛的时候遇到这个题第一个反应就是原题,然后用了以前的代码,WA:单向边,以前代码上是双向边.TLE:这个题出题人还卡了一下网格图.…
262144K   There are NN cities in the country, and MM directional roads from uu to v(1\le u, v\le n)v(1≤u,v≤n). Every road has a distance c_ici​. Haze is a Magical Girl that lives in City 11, she can choose no more than KK roads and make their distanc…
类似题解 There are NN cities in the country, and MM directional roads from uu to v(1\le u, v\le n)v(1≤u,v≤n). Every road has a distance c_ici​. Haze is a Magical Girl that lives in City 11, she can choose no more than KK roads and make their distances be…
题意: n道题,每道题有ai和bi,完成这道题需要先完成若干道题,完成这道题可以得到分数t*ai+bi,其中t是时间 1s, n<=20 思路: 由n的范围状压,状态最多1e6 然后dfs,注意代码中dfs里的剪枝, 对一个状态statu,因为贪心的取最大值就行,所以及时剪枝 代码: 当时写不出来真是菜的活该 #include<iostream> #include<cstdio> #include<algorithm> #include<cmath>…
Walk Through Squares Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 200    Accepted Submission(s): 57 Problem Description   On the beaming day of 60th anniversary of NJUST, as a military colleg…
Divide Groups Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 423    Accepted Submission(s): 161 Problem Description   This year is the 60th anniversary of NJUST, and to make the celebration mor…
Count The Pairs Time Limit: 20000/10000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 277    Accepted Submission(s): 150 Problem Description   With the 60th anniversary celebration of Nanjing University of Science…
题目顺序:A C E G I J L A. An Olympian Math Problem 打表,找规律,发现答案为n-1 C. GDY 题意: m张卡片,标号1-13: n个玩家,标号1-n:每个人拿前5个卡片 玩家1先出牌(最小),其他玩家2-n顺时针标号从1-n-1出牌 轮到当前玩家出牌,如果有比上一次的出牌大1,可以直接出:没有大1的牌,若有2出2:若都没有,这一轮跳过他 如果一轮中,玩家x出了一张最大的牌,玩家x~n,1~x中所有玩家都没有出牌,从玩家x开始所有玩家都拿一张牌(如 果…
2019ICPC南京网络赛A题 The beautiful values of the palace https://nanti.jisuanke.com/t/41298 Here is a square matrix of n * nn∗n, each lattice has its value (nn must be odd), and the center value is n * nn∗n. Its spiral decline along the center of the squar…
南京网络赛自闭现场 https://nanti.jisuanke.com/t/41298 二维偏序经典题型 二维前缀和!!! #include<bits/stdc++.h> using namespace std; #define int long long #define sc(x) scanf("%lld",&x); int T; #define P pair<int,int> #define fi first #define se second #…
题目链接 题意 : 给出一个由数字组成的字符串.然后要你找出其所有本质不同的回文子串.然后将这些回文子串转化为整数后相加.问你最后的结果是多少.答案模 1e9+7 分析 : 应该可以算是回文树挺裸的题目吧 可惜网络赛的时候不会啊.看着马拉车想半天.卒... 对于每一个节点.记录其转化为整数之后的值 然后在回文串插入字符的时候 不断维护这个信息就行了 其实很好理解.看一下代码就懂了 ( 如果你学过回文树的话... ) 就是多加了变量 val .维护语句 #include<bits/stdc++.h…
题意: 就是使不大于k条路的权值变为零后求最短路 解析: d[i][j]表示使j条路变为权值后从起点到点i的最短路径 这题不能用spfa做  tle #include <iostream> #include <cstdio> #include <sstream> #include <cstring> #include <map> #include <cctype> #include <set> #include <v…
30.43% 2000ms 262144K Feeling hungry, a cute hamster decides to order some take-away food (like fried chicken for only 3030 Yuan). However, his owner CXY thinks that take-away food is unhealthy and expensive. So she demands her hamster to fulfill a m…
样例输入复制 2 3 3 0 3 3 1 2 2 样例输出复制 Case #1: 36 Case #2: 20 题目来源 ACM-ICPC 2018 南京赛区网络预赛 题意: 就是求图中去掉涂黑的方格后还剩多少长方形 解析: 这个讲的非常好了 https://blog.csdn.net/Sirius_han/article/details/82313029 对于一个长为L, 高为H的无黑点矩阵中包含的高为H的子矩阵个数为L+(L-1)+(L-2)+...+1个:这是直接算的一种方法:如何程序表示…
During tea-drinking, princess, amongst other things, asked why has such a good-natured and cute Dragon imprisoned Lpl in the Castle? Dragon smiled enigmatically and answered that it is a big secret. After a pause, Dragon added: - We have a contract.…
19.32% 1000ms 256000K A number is skr, if and only if it's unchanged after being reversed. For example, "12321", "11" and "1" are skr numbers, but "123", "221" are not. FYW has a string of numbers, each su…
校赛打杂没施展开. 题意:一开始给你一颗 (0,0)到(0,l)的树. 这棵树每一年会长出来三个幼芽(雾),长度均为l/4,方向分别是左转60,右转60,和不变. 年份<=14 考虑3^14直接暴力存边然后考虑每条边贡献.发现奇难无比. 考虑剪枝. 注意到如果一根树枝的被砍掉了那么他所有的孩子全都不算贡献了.妙啊!变成傻逼题. 抄一下板子. #include <bits/stdc++.h> using namespace std; typedef double db; ; ); int…
A square-free integer is an integer which is indivisible by any square number except 11. For example, 6 = 2 \cdot 36=2⋅3 is square-free, but 12 = 2^2 \cdot 312=22⋅3 is not, because 2^222 is a square number. Some integers could be decomposed into prod…
Dlsj is competing in a contest with n (0 < n \le 20)n(0<n≤20) problems. And he knows the answer of all of these problems. However, he can submit ii-th problem if and only if he has submitted (and passed, of course) s_isi​ problems, the p_{i, 1}pi,1​…
AC Challenge 30.04% 1000ms 128536K   Dlsj is competing in a contest with n (0 < n \le 20)n(0<n≤20) problems. And he knows the answer of all of these problems. However, he can submit ii-th problem if and only if he has submitted (and passed, of cours…
题目链接:https://nanti.jisuanke.com/t/30996 During tea-drinking, princess, amongst other things, asked why has such a good-natured and cute Dragon imprisoned Lpl in the Castle? Dragon smiled enigmatically and answered that it is a big secret. After a pau…
题目链接:https://nanti.jisuanke.com/t/30990 Alice, a student of grade 6, is thinking about an Olympian Math problem, but she feels so despair that she cries. And her classmate, Bob, has no idea about the problem. Thus he wants you to help him. The proble…