poj2491

简单题

#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
using namespace std;

#define maxn 400
#define maxl 100

char st[maxn][maxl];
int n, m;
int from[maxn];
int to[maxn];

int getid(char *a)
{
    for (int i = 0; i < m; i++)
        if (strcmp(st[i], a) == 0)
            return i;
    strcpy(st[m++], a);
    return m - 1;
}

void input()
{
    char a[maxl], b[maxl];
    scanf("%d", &n);
    n--;
    m = 0;
    memset(from, -1, sizeof(from));
    memset(to, -1, sizeof(to));
    for (int i = 0; i < n; i++)
    {
        scanf("%s%s", a, b);
        int x = getid(a);
        int y = getid(b);
        from[y] = x;
        to[x] = y;
    }
}

void work()
{
    int start;
    for (int i = 0; i < m; i++)
        if (from[i] == -1)
        {
            start = i;
            break;
        }
    while (start != -1)
    {
        printf("%s\n", st[start]);
        start = to[start];
    }
}

int main()
{
    //freopen("t.txt", "r", stdin);
    int t;
    scanf("%d", &t);
    for (int i = 0; i < t; i++)
    {
        printf("Scenario #%d:\n", i + 1);
        input();
        work();
        putchar('\n');
    }
    return 0;
}