简单题

#include 
      
        #include 
       
         #include 
        
          #include 
         
           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; }