delete pics to save space

1.1613.cpp

@@ -0,0 +1,34 @@
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+using namespace std;
+const int maxn=55;
+const int maxlongint=64;
+int n,m;
+bool arv[maxn][maxn][maxlongint];
+int d[maxn][maxn];
+int main()
+{
+	scanf("%d%d",&n,&m);
+	memset(d,0x3F,sizeof(d));
+	for(int i=0;i<m;i++)
+	{
+		int u,v; scanf("%d%d",&u,&v);
+		arv[u][v][0]=true; d[u][v]=1;
+	}
+	for(int k=1;k<maxlongint;k++)
+		for(int M=1;M<=n;M++)
+			for(int u=1;u<=n;u++)
+				for(int v=1;v<=n;v++)
+					if(arv[u][M][k-1]&&arv[M][v][k-1])
+					{
+						arv[u][v][k]=true;
+						d[u][v]=1;
+					}
+	for(int M=1;M<=n;M++)
+		for(int u=1;u<=n;u++)
+			for(int v=1;v<=n;v++)
+				d[u][v]=min(d[u][v],d[u][M]+d[M][v]);
+	printf("%d\n",d[1][n]);
+	return 0;
+}