P1649 [USACO07OCT]障碍路线Obstacle Course 题目描述 Consider an N x N (1 <= N <= 100) square field composed of 1 by 1 tiles. Some of these tiles are impassible by cows and are marked with an 'x' in this 5 by 5 field that is challenging to navigate: . . B x .…

P1649 [USACO07OCT]障碍路线Obstacle Course bfs 直接上个bfs 注意luogu的题目和bzoj有不同(bzoj保证有解,还有输入格式不同). #include<iostream> #include<cstdio> #include<cstring> #include<queue> using namespace std; #define pi pair<int,int> #define mkp make_pai…

题目描述 Consider an N x N (1 <= N <= 100) square field composed of 1 by 1 tiles. Some of these tiles are impassible by cows and are marked with an 'x' in this 5 by 5 field that is challenging to navigate: . . B x . . x x A . . . . x . . x . . . . . x .…

题目描述 Consider an N x N (1 <= N <= 100) square field composed of 1 by 1 tiles. Some of these tiles are impassible by cows and are marked with an 'x' in this 5 by 5 field that is challenging to navigate: . . B x . . x x A . . . . x . . x . . . . . x .…

题目描述 Consider an N x N (1 <= N <= 100) square field composed of 1 by 1 tiles. Some of these tiles are impassible by cows and are marked with an 'x' in this 5 by 5 field that is challenging to navigate: . . B x . . x x A . . . . x . . x . . . . . x .…

题目描述 Consider an N x N (1 <= N <= 100) square field composed of 1 by 1 tiles. Some of these tiles are impassible by cows and are marked with an 'x' in this 5 by 5 field that is challenging to navigate: . . B x . . x x A . . . . x . . x . . . . . x .…

P1649 [USACO07OCT]障碍路线Obstacle Course 裸的dfs,今天学了一个新招,就是在过程中进行最优性减枝. #include<bits/stdc++.h> using namespace std; ; ][]; ][]; ,,,}; ,,,-}; ][]; void dfs(int nx,int ny,int dir,int num) { ||ny>n||ny<||vis[nx][ny]||ans==) return; if(a[nx][ny]=='x'…

洛谷 P4478 [BJWC2018]上学路线 原题 神仙题orz,竟然没有1A....容斥+卢卡斯+crt?? 首先用容斥做,记\(f[i][0/1]\)表示到i号点经过了奇数/偶数个点的方案数,因为\(f[i][0]+f[i][1]=1\)所以只要记一个\(f[i]\)是经过奇数个点的方案数就行 枚举一个左下的点走到这个点,或者直接从1走到这个点, \(f[i]=\sum_{\text{j in lower left side}}((1-f[j])\times C_{x_i+y_i-x_j-…

P2233 [HNOI2002]公交车路线 题目背景 在长沙城新建的环城公路上一共有8个公交站,分别为A.B.C.D.E.F.G.H.公共汽车只能够在相邻的两个公交站之间运行,因此你从某一个公交站到另外一个公交站往往要换几次车,例如从公交站A到公交站D,你就至少需要换3次车. Tiger的方向感极其糟糕,我们知道从公交站A到公交E只需要换4次车就可以到达,可是tiger却总共换了n次车,注意tiger一旦到达公交站E,他不会愚蠢到再去换车.现在希望你计算一下tiger有多少种可能的乘车方案. 题…

输入输出样例 输入样例#1: 1 3 10 1 3 1 1 1 3 3 1 30 2 5 7 4 5 2 1 8 6 8 8 11 6 3 输出样例#1: 47.5 import java.util.Scanner; //洛谷 public class car的旅行路线 { public static void main(String[] args) { // TODO Auto-generated method stub Scanner in = new Scanner(System.in);…