poj 2394 Checking a Alibi-dijkstra
来源:互联网 发布:如何评价三国演义 知乎 编辑:程序博客网 时间:2024/05/04 03:44
Checking an Alibi
Time Limit: 1000MS Memory Limit: 65536K
Total Submissions: 5521 Accepted: 2009
Description
A crime has been comitted: a load of grain has been taken from the barn by
one of FJ's cows. FJ is trying to determine which of his C (1 <= C <= 100)
cows is the culprit. Fortunately, a passing satellite took an image of his
farm M (1 <= M <= 70000) seconds before the crime took place, giving the
location of all of the cows. He wants to know which cows had time to get
to the barn to steal the grain.
Farmer John's farm comprises F (1 <= F <= 500) fields numbered 1..F and
connected by P (1 <= P <= 1,000) bidirectional paths whose traversal time
is in the range 1..70000 seconds (cows walk very slowly). Field 1 contains
the barn. It takes no time to travel within a field (switch paths).
Given the layout of Farmer John's farm and the location of each cow when
the satellite flew over, determine set of cows who could be guilty.
NOTE: Do not declare a variable named exactly 'time'. This will reference
the system call and never give you the results you really want.
Input
* Line 1: Four space-separated integers: F, P, C, and M
* Lines 2..P+1: Three space-separated integers describing a path: F1,F2,
and T. The path connects F1 and F2 and requires T seconds to traverse.
* Lines P+2..P+C+1: One integer per line, the location of a cow. The first
line gives the field number of cow 1, the second of cow 2, etc.
Output
* Line 1: A single integer N, the number of cows that could be guilty of
the crime.
* Lines 2..N+1: A single cow number on each line that is one of the cows
that could be guilty of the crime. The list must be in ascending order.
Sample Input
7 6 5 8
1 4 2
1 2 1
2 3 6
3 5 5
5 4 6
1 7 9
1
4
5
3
7
Sample Output
4
1
2
3
4
Hint
INPUT DETAILS:
Fields/distances like this:
6
4------5
| |
2| |
| |
7-----1 |5
9 | |
1| |
| |
2------3
OUTPUT DETAILS:
Any cow except cow 5 could have done it. Cow 5 would take 9 seconds to get
to the barn
//错了n次。代码虽然水,但是就是初始化的问题还是存在,调用init函数居然wa,汗
果断改成:memset(map,0x3f,sizeof(map));
讲一下题目的意思:求从顶点1到各个顶点满足路径小于M的结点的顺序,记录下个数并
输出各个结点的顺序
代码:
#include<cstdio>#include<string>#include<cstring>#include<cmath>#include<queue>#include<iostream>#include<algorithm>using namespace std;#define INF 0x3f3f3f3f#define MAX 505#define pf printfint map[MAX][MAX];int dis[MAX]; bool vis[MAX]; int ans[105];int F,P,C,M;void Dijkstra(){memset(vis,false,sizeof(vis));for(int i=1;i<=F;i++)dis[i]=INF;dis[1]=0;for (int i=1;i<=F;i++) {int k=0,MIN=INF;for (int j=1;j<=F;j++) {if (!vis[j]&& dis[j]<MIN){MIN=dis[j];k=j;}}vis[k]=true;for(int j=1;j<=F;j++) {if(map[k][j]!=INF &&dis[j]>dis[k]+map[k][j])dis[j]=dis[k]+map[k][j];}}}void init(){for(int i=1;i<=F;i++)for(int j=1;j<=F;j++){map[i][j]=0x3f;}}int main () {scanf("%d%d%d%d",&F,&P,&C,&M);int i,a,b,T;memset(map,0x3f,sizeof(map));//init();memset(ans,0,sizeof(ans));for(int i=0;i<P;i++){scanf("%d%d%d",&a,&b,&T);map[a][b]=map[b][a]=min(map[a][b],T);}Dijkstra();int cow,num=0;for(int i=1;i<=C;i++){scanf("%d",&cow);if (dis[cow]<=M)ans[num++]=i;}pf("%d\n",num);for(int i=0;i<num;i++)pf("%d\n",ans[i]);return 0;}
- poj 2394 Checking a Alibi-dijkstra
- poj 2394 Checking an Alibi--(Dijkstra)
- POJ 2394 Checking an Alibi (最短路+Dijkstra)
- poj 2394 Checking an Alibi
- poj 2394 Checking an Alibi
- POJ 2394 Checking an Alibi【SPFA】
- POJ Checking an Alibi
- POJ2394 Checking an Alibi【Dijkstra】
- PKU 2394 ( Checking an Alibi )(Dijkstra 最短路径)
- POJ 2394 Checking an Alibi(最短路)
- POJ 2394 Checking an Alibi 简单最短路
- POJ2394,Checking an Alibi,Dijkstra单源最短路
- PKU 2394---Checking an Alibi
- Checking an Alibi(最短路径 Dijkstra)
- poj 2394 Checking an Alibi(dij+h…
- pku2394 Checking an Alibi
- Checking an Alibi
- POJ2394 Checking an Alibi 最短路
- OpenGl的glMatrixMode()函数理解
- BackTrack5完全配置
- CLisp 26:测试框架fiveam
- Spring+Struts
- timus 1017
- poj 2394 Checking a Alibi-dijkstra
- smarty 优化页面
- 史上最强大vim配置文件
- 万事开头难
- JAVA 类集
- winpcap编程-1
- vpn---设置
- do…while(0)的妙用
- 2013 又一个365