题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=4941 Magical Forest Description There is a forest can be seen as $N * M$ grid. In this forest, there is some magical fruits, These fruits can provide a lot of energy, Each fruit has its location$(X_i, Y_…

Magical Forest Time Limit: 24000/12000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 724    Accepted Submission(s): 343 Problem Description There is a forest can be seen as N * M grid. In this forest, there is so…

Magical Forest Time Limit: 24000/12000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others) Total Submission(s): 135    Accepted Submission(s): 69 Problem Description There is a forest can be seen as N * M grid. In this forest, there is so…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4941 解题报告:给你一个n*m的矩阵,矩阵的一些方格中有水果,每个水果有一个能量值,现在有三种操作,第一种是行交换操作,就是把矩阵的两行进行交换,另一种是列交换操作,注意两种操作都要求行或列至少要有一个水果,第三种操作是查找,询问第A行B列的水果的能量值,如果查询的位置没有水果,则输出0. 因为n和m都很大,达到了2*10^9,但水果最多一共只有10^5个,我的做法是直接用结构体存了之后排序,然后m…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4941 题目大意:给你10^5个点.每一个点有一个数值.点的xy坐标是0~10^9.点存在于矩阵中.然后给出10^5个操作.1代表交换行.2代表交换列,3代表查询坐标为xy点的数值. 数据量非常大........ 所以一直没有思路 后来赛后看了题解是先用离散化然后存在线性map里面. 用hx,hy来存放离散化后的点的坐标,用linkx,linky来存放点离散化之后的点的坐标的行与列. 还是对于STL里…

思路:将行列离散化,那么就可以用vector 存下10W个点 ,对于交换操作 只需要将行列独立分开标记就行   . r[i] 表示第 i 行存的是 原先的哪行         c[j] 表示 第 j 列 存的是原先的哪列. 查询只需要一个二分即可. #include <iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<cmath> #include&…

题意: 有n*m个格子(n,m <= 2*10^9),有k(k<=10^5)个格子中有值,现在有三种操作,第一种为交换两行,第二种为交换两列,交换时只有两行或两列都有格子有值或都没有格子有值时才能交换,第三种操作是询问现在第A行第B列值为多少. 解法:格子太大,但是k比较小,所以考虑离散一下,把行离散出来,最多10^5行,列用map存下即可. nowR[i] = j 时表示现在的第 i 行是原来的第 j 行, nowC表示列的 R[]表示该行有没有值, CntC[]表示列 然后交换时直交换上面…

题目链接 题意: 有一个n*m的田地,里边有k棵树,每棵树的位置为(xi,yi),含有能量值ci.之后又q个询问,分三种; 1)1 a b,将a行和b行交换 2)2 a b,将a列和b列交换 3)3 a b,询问(a,b)位置的果树的能量值. 分析:由于n和m很大,而k很小,所以可以用map离散化.每次交换行或者列的时候只需交换map映射的值即可. 交换的时候只是交换离散以后的代号就行,mp[][]里面还是原来的. #include <iostream> #include <cstdio…

这个题比赛的时候是乱搞的,比赛结束之后学长说是映射+hash才恍然大悟.因此决定好好学一下hash. 题意: M*N的格子,里面有一些格子里面有一个值. 有三种操作: 1.交换两行的值. 2.交换两列的值. 3.询问某个格子的值. 保证,交换的时候要么两行都有值,要么两行都为空. 思路: 其实交换两行或者两列的话,相当于把那两行的对应下标交换一下.因此我们可以想到,对行标和列表建立一个索引,交换的时候,我们只需要交换一下索引. 因为行和列比较多,所以我们不能直接存整个矩阵,即使离散化也不可以,所…

2014多校7最水的题   Magical Forest Magical Forest Time Limit: 24000/12000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others) Total Submission(s): 253    Accepted Submission(s): 120 Problem Description    There is a forest can be seen as N * M…

Magical Forest Time Limit: 24000/12000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others) Total Submission(s): 134    Accepted Submission(s): 69 Problem Description    There is a forest can be seen as N * M grid. In this forest, there is…

Magical Forest Problem Description There is a forest can be seen as N * M grid. In this forest, there is some magical fruits, These fruits can provide a lot of energy, Each fruit has its location(Xi, Yi) and the energy can be provided Ci. However, th…

Problem Description There is a forest can be seen as N * M grid. In this forest, there is some magical fruits, These fruits can provide a lot of energy, Each fruit has its location(Xi, Yi) and the energy can be provided Ci. However, the forest will m…

http://acm.hdu.edu.cn/showproblem.php?pid=4941 给定N,M和K,表示在一个N*M的棋盘上有K个棋子,给出K个棋子的位置和值,然后是Q次操作,对应的是: 1 a b :交换a和b两行 2 a b : 交换a和b两列 3 a b :查询a b这个位置上棋子的值,没有棋子的话输出0 不能直接模拟,对应行列交换,只需交换map映射值,查询时输出map[x],map[y]上值即可 #include <cstdio> #include <cstdlib&…

Problem Description There is a forest can be seen as N * M grid. In this forest, there is some magical fruits, These fruits can provide a lot of energy, Each fruit has its location(Xi, Yi) and the energy can be provided Ci.  However, the forest will…

#include<iostream> #include<cstdio> #include<cstring> #include<map> using namespace std; typedef struct node{ int x,y; bool operator<(const node &b)const { if(x==b.x) return y<b.y; else return x<b.x; } }node; int main(…

题意 给你n个点m条边,并且保证整个图是仙人掌. 仙人掌:每条边仅属于1条或者0条回路 且无重边和自环 让你删掉一些边使其变成一棵树(拥有点数-1条边) 注意一个点也是森林 图可能是不联通的 思路 考虑环,显然一个环可以随便去掉几条边但是至少一条(也就是说不能是\(C_n^0\))\(2^{x}\)-1,然后考虑非环那么共有m-(所有环的边数),然后可以随便去除边共\(2^{m-cnt}\) 在找环时,求环的边数见\(dfs\) #include<iostream> #include<a…

官方解题报告:http://blog.sina.com.cn/s/blog_a19ad7a10102uzd4.html Magical Forest http://acm.hdu.edu.cn/showproblem.php?pid=4941 #include<cstdio> #include<map> using namespace std; typedef pair<int,int> pii; map<pii,int> cost; map<int,…

A - Couple doubi 这种题不要想复杂,直接找规律.找不出规律就打表找规律 #include <iostream> #include <string> #include <cstring> #include <cstdlib> #include <cstdio> #include <cmath> #include <algorithm> #include <stack> #include <q…

题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=5154 Harry and Magical Computer Description In reward of being yearly outstanding magic student, Harry gets a magical computer. When the computer begins to deal with a process, it will work until the end…

A Walk Through the Forest Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4383    Accepted Submission(s): 1573 Problem Description Jimmy experiences a lot of stress at work these days, especiall…

A Walk Through the Forest 题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=1142 Description Jimmy experiences a lot of stress at work these days, especially since his accident made working difficult. To relax after a hard day, he likes to walk home. T…

Harry Potter and the Forbidden Forest Time Limit: 5000/3000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 2089    Accepted Submission(s): 702 Problem Description Harry Potter notices some Death Eaters try to slip…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5154 题目意思:有 n 门 processes(编号依次为1,2,...,n),然后给出 m 种关系: a,b.表示 process b 要在 process a 之前完成.问经过 m 种关系之后,有没有可能完成所有的 process. 可以利用拓扑排序的思想做.遍历所有 process,处理所有入度为 0 的点,然后把与该点关联的点,即度数都减一.这样处理完之后,每个点的度数应该都是-1,否则就代…

view code//hdu 3987 #include <iostream> #include <cstdio> #include <algorithm> #include <cstring> #include <queue> using namespace std; typedef long long ll; const ll INF = 1LL<<59; const ll E = 100001; const int N = 10…

Harry and Magical Computer Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Problem Description In reward of being yearly outstanding magic student, Harry gets a magical computer. When the computer begins to deal wi…

原题链接:http://acm.hdu.edu.cn/showproblem.php?pid=1142 题目大意:Jimmy要从办公室走路回家,办公室在森林的一侧,家在另一侧,他每天要采取不一样的路线回家.由于他要尽快回家,他在选择路线的时候总是要越来越靠近他家.计算符合条件的路线一共有几种. 解题思路:题目要求“路线要越来越靠近家”,也就是说每次选择下一个结点的时候距离家的距离比当前的结点近.首先该结点离家的距离就是该节点到家的最短路径的长度.所以我们先求出所有节点到家的最短路径.(Dijks…

http://acm.hdu.edu.cn/showproblem.php?pid=1142 这道题是spfa求最短路,然后dfs()求路径数. #include <cstdio> #include <queue> #include <cstring> #include <algorithm> #define maxn 1001 using namespace std; <<; int g[maxn][maxn]; int dis[maxn];…

Description In reward of being yearly outstanding magic student, Harry gets a magical computer. When the computer begins to deal with a process, it will work until the ending of the processes. One day the computer got n processes to deal with. We num…

Harry and Magical Computer Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 499    Accepted Submission(s): 233 Problem Description In reward of being yearly outstanding magic student, Harry gets…