PAT (Advanced Level) 1111. Online Map (30)

#include<cstdio>
#include<cstring>
#include<cmath>
#include<vector>
#include<map>
#include<queue>
#include<stack>
#include<algorithm>
using namespace std;

int n,m;
int st,en;
struct Edge
{
int u,v,len,time;
}e[2000000+10];
int tot=0;
vector<int>g[600];
int Dis[600],Tim[600];
bool flag[600];

int ans_len,ans_time,ans_sz,ans_count;
int path[600],ans_path[600];

vector<int>p1,p2;
int Distance,Time;

void addedge(int u,int v,int len,int time)
{
e[tot].u=u; e[tot].v=v; e[tot].len=len; e[tot].time=time;
g[u].push_back(tot++);
}

void SPFA(int s)
{
queue<int>Q;
memset(flag,0,sizeof flag);
for(int i=0;i<=n;i++) Dis[i]=99999999;
Q.push(s); flag[s]=1; Dis[s]=0;
while(!Q.empty())
{
int head=Q.front(); Q.pop(); flag[head]=0;
for(int i=0;i<g[head].size();i++)
{
int id=g[head][i];
if(Dis[head]+e[id].len<Dis[e[id].v])
{
Dis[e[id].v]=Dis[head]+e[id].len;
if(flag[e[id].v]==0)
{
flag[e[id].v]=1;
Q.push(e[id].v);
}
}
}
}

memset(flag,0,sizeof flag);
for(int i=0;i<=n;i++) Tim[i]=99999999;
Q.push(s); flag[s]=1; Tim[s]=0;
while(!Q.empty())
{
int head=Q.front(); Q.pop(); flag[head]=0;
for(int i=0;i<g[head].size();i++)
{
int id=g[head][i];
if(Tim[head]+e[id].time<Tim[e[id].v])
{
Tim[e[id].v]=Tim[head]+e[id].time;
if(flag[e[id].v]==0)
{
flag[e[id].v]=1;
Q.push(e[id].v);
}
}
}
}
}

void dfs1(int x,int len,int time,int dep)
{
if(len>ans_len) return;

if(x==en)
{
if(len<ans_len)
{
ans_len=len;
ans_time=time;
ans_sz=dep;
for(int i=0;i<dep;i++)
ans_path[i]=path[i];
}
else if(len==ans_len)
{
if(time<ans_time)
{
ans_time=time;
ans_sz=dep;
for(int i=0;i<dep;i++)
ans_path[i]=path[i];
}
}
return;
}
for(int i=0;i<g[x].size();i++)
{
int id=g[x][i];
path[dep]=e[id].v;
if(Dis[x]+e[id].len>Dis[e[id].v]) continue;
dfs1(e[id].v,len+e[id].len,time+e[id].time,dep+1);
}
}

void dfs2(int x,int time,int count,int dep)
{
if(time>ans_time) return;

if(x==en)
{
if(time<ans_time)
{
ans_time=time;
ans_count=count;
ans_sz=dep;
for(int i=0;i<dep;i++)
ans_path[i]=path[i];
}
else if(time==ans_time)
{
if(count<ans_count)
{
ans_count=count;
ans_sz=dep;
for(int i=0;i<dep;i++)
ans_path[i]=path[i];
}
}
return;
}
for(int i=0;i<g[x].size();i++)
{
int id=g[x][i];
path[dep]=e[id].v;
if(Tim[x]+e[id].time>Tim[e[id].v]) continue;
dfs2(e[id].v,time+e[id].time,count+1,dep+1);
}
}

int main()
{
scanf("%d%d",&n,&m);
for(int i=1;i<=m;i++)
{
int u,v,f,len,time;
scanf("%d%d%d%d%d",&u,&v,&f,&len,&time);
addedge(u,v,len,time);
if(f==0) addedge(v,u,len,time);
}
scanf("%d%d",&st,&en);

SPFA(st);

for(int i=0;i<=n;i++) flag[i]=9999999;
ans_len=9999999;
ans_time=9999999; flag[st]=0;
dfs1(st,0,0,0);

Distance = ans_len;
p1.push_back(st);
for(int i=0;i<ans_sz;i++) p1.push_back(ans_path[i]);

for(int i=0;i<=n;i++) flag[i]=9999999;
ans_time=9999999;
ans_count=9999999; flag[st]=0;
dfs2(st,0,0,0);

Time=ans_time;
p2.push_back(st);
for(int i=0;i<ans_sz;i++) p2.push_back(ans_path[i]);

bool fail=0;
if(p1.size()!=p2.size()) fail=1;
else {
for(int i=0;i<p1.size();i++)
if(p1[i]!=p2[i]) fail=1;
}

if(fail==0)
{
printf("Distance = %d; Time = %d: ",Distance,Time);
for(int i=0;i<p1.size();i++)
{
printf("%d",p1[i]);
if(i<p1.size()-1) printf(" -> ");
else printf("\n");
}
}
else
{
printf("Distance = %d: ",Distance);
for(int i=0;i<p1.size();i++)
{
printf("%d",p1[i]);
if(i<p1.size()-1) printf(" -> ");
else printf("\n");
}

printf("Time = %d: ",Time);
for(int i=0;i<p2.size();i++)
{
printf("%d",p2[i]);
if(i<p2.size()-1) printf(" -> ");
else printf("\n");
}

}
return 0;
}