delete pics to save space

7.1734.cpp

@@ -0,0 +1,56 @@
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+#include<vector>
+using namespace std;
+typedef long long LL;
+const int maxn=305;
+const int oo=0x3f3f3f3f;
+int a[maxn][maxn],d[maxn][maxn],p[maxn][maxn];
+int n,m,res;
+vector<int> sol;
+void dfs(int L,int R)
+{
+	if(p[L][R]==0) return;
+	dfs(L,p[L][R]);
+	sol.push_back(p[L][R]);
+	dfs(p[L][R],R);
+}
+int main()
+{
+	#ifdef local
+	freopen("pro.in","r",stdin);
+	#endif
+	scanf("%d%d",&n,&m);
+	memset(a,0x3f,sizeof(a));
+	for(int i=1;i<=n;i++) a[i][i]=0;
+	for(int i=1;i<=m;i++)
+	{
+		int x,y,z; scanf("%d%d%d",&x,&y,&z);
+		a[y][x]=a[x][y]=min(a[x][y],z);
+	}
+	memcpy(d,a,sizeof(a));
+	res=oo;
+	for(int k=1;k<=n;k++)
+	{
+		for(int i=1;i<k;i++)
+			for(int j=i+1;j<k;j++)
+				if((LL)d[i][j]+a[j][k]+a[k][i]<res)
+				{
+					res=d[i][j]+a[j][k]+a[k][i];
+					sol.clear();
+					sol.push_back(i);
+					dfs(i,j);
+					sol.push_back(j);
+					sol.push_back(k);
+				}
+		for(int i=1;i<=n;i++) for(int j=1;j<=n;j++) if(d[i][k]+d[k][j]<d[i][j])
+		{
+			d[i][j]=d[i][k]+d[k][j];
+			p[i][j]=k;
+		}
+	}
+	if(res==oo) { puts("No solution."); return 0; }
+	for(int i=0;i<sol.size();i++) printf("%d ",sol[i]); puts("");
+	return 0;
+}