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;

}