【POJ 1125】Stockbroker Grapevine

#include

using namespace std;

int dis[111][111],n;

void Floyd()
{
int i,j,k,tmax,mmax,f;

for(k = 1; k <= n; ++k)
for(i = 1; i <= n; ++i)
for(j = 1; j <= n; ++j)
if(dis[i][j] > dis[i][k] + dis[k][j])
dis[i][j] = dis[i][k] + dis[k][j];
mmax = INF;

for(i = 1; i <= n; ++i)
{
f = 1;
tmax = 0;
for(j = 1; j <= n; ++j)
{
if(i == j) continue;
if(dis[i][j] == INF) f = 0;
tmax = max(tmax,dis[i][j]);
}
if(f && tmax < mmax)
{
k = i;
mmax = tmax;
}
}
if(mmax != INF) printf("%d %d\n",k,mmax);
else puts("disjoint");
}

int main()
{
int i,k,v;
while(~scanf("%d",&n) && n)
{
memset(dis,INF,sizeof(dis));
for(i = 1; i <= n; ++i)
{
scanf("%d",&k);
while(k--)
{
scanf("%d",&v);
scanf("%d",&dis[i][v]);
}
}
Floyd();
}

return 0;
}

#include

using namespace std;

typedef struct Edge
{
int v,w,next;
}Edge;

Edge eg[11111];
int head[111],dis[111],n,tp;
bool vis[111];

int Dijkstra(int u)
{
memset(dis,INF,sizeof(dis));
memset(vis,0,sizeof(vis));
dis[u] = 0;

int m,p,i,j;

for(i = 1; i <= n; ++i)
{
p = -1;
m = INF;
for(j = 1; j <= n; ++j)
{
if(!vis[j] && dis[j] < m)
{
p = j;
m = dis[j];
}
}
if(i == n || p == -1) break;
vis[p] = 1;

for(j = head[p]; j != -1; j = eg[j].next)
{
if(!vis[eg[j].v] && dis[eg[j].v] > dis[p] + eg[j].w)
dis[eg[j].v] = dis[p] + eg[j].w;
}

}
if(p == -1) return INF;
return dis[p];
}

int main()
{
int i,k,m,t;
while(~scanf("%d",&n) && n)
{
m = INF;
tp = 0;
memset(head,-1,sizeof(head));
for(i = 1; i <= n; ++i)
{
scanf("%d",&k);
while(k--)
{
scanf("%d %d",&eg[tp].v,&eg[tp].w);
eg[tp].next = head[i];
head[i] = tp++;
}
}
k = 0;
for(i = 1; i <= n; ++i)
{
t = Dijkstra(i);
if(t < m)
{
k = i;
m = t;
}
}
if(k)
printf("%d %d\n",k,m);
else puts("disjoint");
}

return 0;
}

#include

using namespace std;

typedef struct Edge
{
int v,w,next;
}Edge;

Edge eg[11111];
int head[111],dis[111],n,tp;
bool vis[111];

int SPFA(int u)
{
memset(dis,INF,sizeof(dis));
memset(vis,0,sizeof(vis));
dis[u] = 0;
queue <int> q;
q.push(u);
int v,w,i,p,m;

while(!q.empty())
{
p = q.front();
q.pop();
vis[u] = 0;
for(i = head[p]; i != -1; i = eg[i].next)
{
v = eg[i].v;
w = eg[i].w;
if(dis[v] > dis[p] + w)
{
dis[v] = dis[p] + w;
if(!vis[v])
{
vis[v] = 1;
q.push(v);
}
}
}
}
m = 0;
for(i = 1; i <= n; ++i)
{
if(i == u) continue;
if(dis[i] == INF) return INF;
m = max(m,dis[i]);
}
return m;
}

int main()
{
int i,k,m,t;
while(~scanf("%d",&n) && n)
{
m = INF;
tp = 0;
memset(head,-1,sizeof(head));
for(i = 1; i <= n; ++i)
{
scanf("%d",&k);
while(k--)
{
scanf("%d %d",&eg[tp].v,&eg[tp].w);
eg[tp].next = head[i];
head[i] = tp++;
}
}
k = 0;
for(i = 1; i <= n; ++i)
{
t = SPFA(i);
if(t < m)
{
k = i;
m = t;
}
}
if(k)
printf("%d %d\n",k,m);
else puts("disjoint");
}

return 0;
}