Files
OI-source/2.208.cpp
2023-08-03 09:22:52 +08:00

52 lines
1.1 KiB
C++

#include <cstdio>
#include <cstring>
const int maxn = 999999;
int t = 0, v, sum, f;
int g[30][30], vis[30], floyd[30][30], rec[30];
void dfs(int x, int n) {
if (x == f) {
printf("1");
for (int i = 1; i < n - 1; i++)
printf(" %d", rec[i]);
printf(" %d\n", f);
sum++;
return;
}
for (int i = 1; i <= v; i++) {
if (!vis[i] && g[x][i] == 1 && floyd[f][i] != maxn) {
rec[n] = i;
vis[i] = 1;
dfs(i, n + 1);
vis[i] = 0;
}
}
}
int main() {
int x, y, cas = 1;
while (scanf("%d", &f) != EOF) {
v = 0;
for (int i = 1; i <= 21; i++)
for (int j = 1; j <= 21; j++)
g[i][j] = floyd[i][j] = maxn;
while (scanf("%d%d", &x, &y) && (x || y)) {
g[x][y] = g[y][x] = 1;
floyd[x][y] = floyd[y][x] = 1;
if (x > v) v = x;
if (y > v) v = y;
}
for (int k = 1; k <= v; k++)
for (int i = 1; i <= v; i++)
for (int j = 1; j <= v; j++)
if (floyd[i][k] + floyd[k][j] < floyd[i][j])
floyd[i][j] = floyd[i][k] + floyd[k][j];
vis[1] = 1;
sum = 0;
printf("CASE %d:\n", cas++);
dfs(1, 1);
printf("There are %d routes from the firestation to streetcorner %d.\n", sum, f);
}
return 0;
}