sgu 103. Traffic Lights

http://acm.sgu.ru/problem.php?contest=0&problem=103

简单的最短路  不过在处理等待时间上有点繁琐

代码：

#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<cmath>
#include<map>
#include<set>
#include<vector>
#include<stack>
#include<queue>

#define ll long long

using namespace std;
const int INF=0x3f3f3f3f;
const int N=305;
int dist[N],pre[N];
int d[N][N];
bool had[N];
struct node
{
    char c;
    int r,tb,tp;
}mem[N];
void M(int t,char &c,int &r,int tb,int tp)
{
    if(t<=r) {r=r-t+1;return ;}
    t=(t-r)%(tb+tp);
    if(t==0)
    {
        if(c=='B') {c='B';r=1;}
        else {c='P';r=1;}
        return ;
    }
    if(c=='P')
    {
        if(t<=tb) {r=tb-t+1;c='B';}
        else {r=(tp-(t-tb))+1;c='P';}
    }else
    {
        if(t<=tp) {r=tp-t+1;c='P';}
        else {r=(tb-(t-tp))+1;c='B';}
    }

}
int F(int t,int l,int r)
{
    char lc=mem[l].c,rc=mem[r].c;
    int lr=mem[l].r,ltb=mem[l].tb,ltp=mem[l].tp;
    int rr=mem[r].r,rtb=mem[r].tb,rtp=mem[r].tp;
    M(t,lc,lr,ltb,ltp);
    M(t,rc,rr,rtb,rtp);
    if(lc==rc)
    return 0;
    if(lr==rr&&ltb==rtp&&ltp==rtb)
    return INF;
    if(lr!=rr)
    return min(lr,rr);
    int tmp=lr;
    if(lc=='B') {lc='P';lr=ltp;}
    else {lc='B';lr=ltb;}
    if(rc=='B') {rc='P';rr=ltp;}
    else {rc='B';rr=rtb;}
    if(lr!=rr)
    return tmp+min(lr,rr);
    tmp+=lr;
    if(lc=='B') {lc='P';lr=ltp;}
    else {lc='B';lr=ltb;}
    if(rc=='B') {rc='P';rr=ltp;}
    else {rc='B';rr=rtb;}
    if(lr!=rr)
    return tmp+min(lr,rr);
    return INF;
}
int dijkstra(int x1,int x2,int n)
{
    memset(had,false,sizeof(had));
    for(int i=1;i<=n;++i)
    dist[i]=INF;
    dist[x1]=0;
    pre[x1]=x1;
    for(int w=1;w<=n;++w)
    {
        int k=-1;
        for(int i=1;i<=n;++i)
        if(!had[i]&&(k==-1||dist[i]<dist[k]))
        k=i;
        if(k==-1||dist[k]==INF||k==x2)
        break;
        had[k]=true;
        for(int i=1;i<=n;++i)
        {
            int tmp=F(dist[k]+1,k,i);
            if(!had[i]&&dist[i]>dist[k]+d[k][i]+tmp)
            {
                dist[i]=dist[k]+d[k][i]+tmp;
                pre[i]=k;
            }
        }
    }
    return dist[x2];
}
int main()
{
    //freopen("data.in","r",stdin);
	int x1,x2;
	while(cin>>x1>>x2)
	{
	    int n,m;
	    cin>>n>>m;
	    for(int i=1;i<=n;++i)
	    cin>>mem[i].c>>mem[i].r>>mem[i].tb>>mem[i].tp;
	    for(int i=1;i<=n;++i)
	    for(int j=1;j<=n;++j)
	    if(i==j) d[i][j]=0;
	    else d[i][j]=INF;
	    while(m--)
	    {
	        int l,r,len;
	        cin>>l>>r>>len;
	        d[l][r]=len;
	        d[r][l]=len;
	    }
	    int T=dijkstra(x1,x2,n);
	    if(T==INF)
	    cout<<"0"<<endl;
	    else
	    {
	        cout<<T<<endl;
	        //for(int i=1;i<=n;++i)
	        //cout<<pre[i]<<" ";cout<<endl;
	        stack<int>st;
	        int k=x2;
	        //cout<<x1<<" "<<x2<<endl;
	        while(k!=x1)
	        {
	            st.push(k);
	            k=pre[k];
	        }
	        //cout<<st.size()<<endl;
	        st.push(k);
	        while(!st.empty())
	        {
	            cout<<(st.top())<<" ";
	            st.pop();
	        }
	        cout<<endl;
	    }
	}
	return 0;
}