Stockbroker Grapevine
| Time Limit: 1000MS | Memory Limit: 10000K | |
| Total Submissions: 33164 | Accepted: 18259 |
Description
Stockbrokers are known to overreact to rumours. You have been contracted to develop a method of spreading disinformation amongst the stockbrokers to give your employer the tactical edge in the stock market. For maximum effect, you have to spread the rumours
in the fastest possible way.
Unfortunately for you, stockbrokers only trust information coming from their "Trusted sources" This means you have to take into account the structure of their contacts when starting a rumour. It takes a certain amount of time for a specific stockbroker to pass
the rumour on to each of his colleagues. Your task will be to write a program that tells you which stockbroker to choose as your starting point for the rumour, as well as the time it will take for the rumour to spread throughout the stockbroker community.
This duration is measured as the time needed for the last person to receive the information.
Input
Your program will input data for different sets of stockbrokers. Each set starts with a line with the number of stockbrokers. Following this is a line for each stockbroker which contains the number of people who they have contact with, who these people are,
and the time taken for them to pass the message to each person. The format of each stockbroker line is as follows: The line starts with the number of contacts (n), followed by n pairs of integers, one pair for each contact. Each pair lists first a number referring
to the contact (e.g. a ‘1‘ means person number one in the set), followed by the time in minutes taken to pass a message to that person. There are no special punctuation symbols or spacing rules.
Each person is numbered 1 through to the number of stockbrokers. The time taken to pass the message on will be between 1 and 10 minutes (inclusive), and the number of contacts will range between 0 and one less than the number of stockbrokers. The number of
stockbrokers will range from 1 to 100. The input is terminated by a set of stockbrokers containing 0 (zero) people.
Output
For each set of data, your program must output a single line containing the person who results in the fastest message transmission, and how long before the last person will receive any given message after you give it to this person, measured in integer minutes.
It is possible that your program will receive a network of connections that excludes some persons, i.e. some people may be unreachable. If your program detects such a broken network, simply output the message "disjoint". Note that the time taken to pass the
message from person A to person B is not necessarily the same as the time taken to pass it from B to A, if such transmission is possible at all.
Sample Input
3 2 2 4 3 5 2 1 2 3 6 2 1 2 2 2 5 3 4 4 2 8 5 3 1 5 8 4 1 6 4 10 2 7 5 2 0 2 2 5 1 5 0
Sample Output
3 2 3 10
这个题目输入确实很变态。。。
题意半天读不懂，最后才发现，是一个求最短路的题目；
输入要求是第一行为 n 表示一共有多少点
第二行 2 表示一个通两个点 2 4表示，从1到2的距离为4
如果联通 输出由哪个点联通所有点距离最短，并求出这个点到其他点距离最大是多少
//floyd
#include <stdio.h>
#include <string.h>
#include <algorithm>
#define inf 0x3f3f3f3f
using namespace std;
int map[105][105];
int n,m;
int main(){
int i,j,k;
while(~scanf("%d",&n)){
if(n==0)
break;
memset(map,inf,sizeof(map));
for(i=1;i<=n;i++){
map[i][i]=0;
}
for(i=1;i<=n;i++){
scanf("%d",&m);
while(m--){
int x,y;
scanf("%d %d",&x,&y);
map[i][x]=min(map[i][x],y); //有向图
}
}
for(k=1;k<=n;k++)
for(i=1;i<=n;i++)
for(j=1;j<=n;j++)
map[i][j]=min(map[i][j],map[i][k]+map[k][j]);
// for(i=1;i<=n;i++){
// for(j=1;j<=n;j++)
// printf("%d ",map[i][j]);
// puts("");
// }
int min = inf;
//printf("%d\n",min);
int t=0;
int flag=0;
for(i=1;i<=n;i++){
int sum=0;
flag=0;
for(j=1;j<=n;j++){
sum+=map[i][j];
if(map[i][j]==inf)
flag=1;
}
//printf("%d\n",sum);
if(flag==0&&sum<min){
min=sum;
t=i;
}
}
int maxx=0;
for(i=1;i<=n;i++){
if(map[t][i]>maxx)
maxx=map[t][i];
}
if(t==0)
printf("disjoint\n");
else
printf("%d %d\n",t,maxx);
}
return 0;
}