poj 2491 Scavenger Hunt

最新推荐文章于 2022-03-24 12:38:32 发布

转载最新推荐文章于 2022-03-24 12:38:32 发布 · 139 阅读

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原文链接：http://www.cnblogs.com/w0w0/archive/2011/11/22/2258563.html

本文介绍了一个有趣的编程挑战：根据一系列连续的步骤对数条记录进行分析，以重建完整的路线。此问题要求从散乱的步骤中找出起始点，并按正确顺序连接所有步骤。

Scavenger Hunt

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 2145		Accepted: 1176

Description

Background
Bill has been the greatest boy scout in America and has become quite a superstar because he always organized the most wonderful scavenger hunts (you know, where the kids have to find a certain route following certain hints). Bill has retired now, but a nationwide election quickly found a successor for him, a guy called George. He does a poor job, though, and wants to learn from Bill's routes. Unfortunately Bill has left only a few notes for his successor.
Problem
Bill never wrote down his routes completely, he only left lots of little sheets on which he had written two consecutive steps of the routes. He then mixed these sheets and memorized his routes similarly to how some people learn for exams: practicing again and again, always reading the first step and trying to remember the following. This made much sense, since one step always required something from the previous step.
George however would like to have a route written down as one long sequence of all the steps in the correct order. Please help him make the nation happy again by reconstructing the routes.

Input

The first line contains the number of scenarios. Each scenario describes one route and its first line tells you how many steps (3 <= S <= 333) the route has. The next S-1 lines each contain one consecutive pair of the steps on the route separated by a single space. The name of each step is always a single string of letters.

Output

The output for every scenario begins with a line containing "Scenario #i:", where i is the number of the scenario starting at 1. Then print S lines containing the steps of the route in correct order. Terminate the output for the scenario with a blank line.

Sample Input

2
4
SwimmingPool OldTree
BirdsNest Garage
Garage SwimmingPool
3
Toilet Hospital
VideoGame Toilet

Sample Output

Scenario #1:
BirdsNest
Garage
SwimmingPool
OldTree

Scenario #2:
VideoGame
Toilet
Hospital

#include<iostream>
#include<map>
#include<string>
using namespace std;
int main()
{
    map<string,string> hunt;
    map<string,int> hunt_count;
int t;
int n;
int num;
string a,b;
string head_tail[2];
int i;
string head;
    cin>>t;
for(n=1;n<=t;n++)
    {
        hunt.clear();
        hunt_count.clear();
        cin>>num;
        num-=1;
while(num--)
        {
            cin>>a;
            cin>>b;
            hunt[a]=b;
            hunt_count[a]++;
            hunt_count[b]++;
        }
        map<string,int>::iterator ite;
        i=0;
for(ite=hunt_count.begin();ite!=hunt_count.end();ite++)
        {
if(ite->second==1)
                head_tail[i++]=ite->first;
        }
for(i=0;i<2;i++)
        {
if(hunt[head_tail[i]].size()!=0)
                head=head_tail[i];
        }
        cout<<"Scenario #"<<n<<":"<<endl<<head<<endl;
while(hunt[head].size()!=0)
        {
            cout<<hunt[head]<<endl;
            head=hunt[head];
        }
        cout<<endl;
    }
return 0;
}

转载于:https://www.cnblogs.com/w0w0/archive/2011/11/22/2258563.html