delete pics to save space

2.208.cpp

@@ -0,0 +1,51 @@
+#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;
+}