Codeforces Codeforces Round #484 (Div. 2) E. Billiard 题目连接: http://codeforces.com/contest/982/problem/E Description Consider a billiard table of rectangular size $n \times m$ with four pockets. Let's introduce a coordinate system with the origin at t…

题意:给你一个台球桌面,一个台球的初始位置和初始速度方向(只可能平行坐标轴或者与坐标轴成45度角),问你能否滚进桌子四个角落的洞里,如果能,滚进的是哪个洞. 如果速度方向平行坐标轴,只需分类讨论,看它是否在台球桌的边沿即可. 如果速度方向和坐标轴成45度,如下图 将整个过程展开, 设出射方向与当前所在桌面的两个边沿的距离分别为X,Y,则有方程X+pn=Y+qm,扩欧可求得解.然后再根据p.q的奇偶性即可确定滚进的是哪个洞(根据图中洞编号的翻折关系).…

Codeforces Codeforces Round #484 (Div. 2) D. Shark 题目连接: http://codeforces.com/contest/982/problem/D Description For long time scientists study the behavior of sharks. Sharks, as many other species, alternate short movements in a certain location and…

Codeforces Beta Round #80 (Div. 2 Only) A Blackjack1 题意 一共52张扑克,A代表1或者11,2-10表示自己的数字,其他都表示10 现在你已经有一个queen了,问你有多少种方案,能够得到n点 题解 其实只用考虑三种情况,都考虑一下就好了,实在不行就暴力枚举-- 代码 #include<bits/stdc++.h> using namespace std; int n; int main() { scanf("%d",&…

Codeforces Beta Round #83 (Div. 1 Only) A. Dorm Water Supply 题意 给你一个n点m边的图,保证每个点的入度和出度最多为1 如果这个点入度为0,那么这个点就是水龙头点. 如果这个点的出度为0,那么这个点就是储存点. 现在让你把所有水龙头到储存点的路径都输出出来,且输出这条路径的边权最小值 题解 显然是个仙人掌图,所以直接XJB暴力就好了 代码 #include<bits/stdc++.h> using namespace std; co…

Codeforces Beta Round #79 (Div. 2 Only) http://codeforces.com/contest/102 A #include<bits/stdc++.h> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define sqr(x) ((x)*(x)) #define pb push_back #define eb empla…

Codeforces Beta Round #77 (Div. 2 Only) http://codeforces.com/contest/96 A #include<bits/stdc++.h> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define sqr(x) ((x)*(x)) #define pb push_back #define eb emplac…

Codeforces Beta Round #76 (Div. 2 Only) http://codeforces.com/contest/94 A #include<bits/stdc++.h> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define sqr(x) ((x)*(x)) #define pb push_back #define eb emplac…

Codeforces Beta Round #75 (Div. 2 Only) http://codeforces.com/contest/92 A #include<iostream> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define sqr(x) ((x)*(x)) #define maxn 100005 typedef long long ll; t…

Codeforces Beta Round #74 (Div. 2 Only) http://codeforces.com/contest/90 A #include<iostream> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define sqr(x) ((x)*(x)) #define maxn 100005 typedef long long ll; t…