POJ 1724 ROADS

Description

Input

Output

Sample Input

5
6
7
1 2 2 3
2 4 3 3
3 4 2 4
1 3 4 1
4 6 2 1
3 5 2 0
5 4 3 2

Sample Output

11

//332K	94MS
#include<stdio.h>
#include<string.h>
#define M 107
#define inf 0x3f3f3f
int head[M],vis[M],nodes,minlen;
int n,m,k;
struct E
{
    int u,v,l,c,next;
} edge[M*M];
void addedge(int u,int v,int l,int c)
{
    edge[nodes].u=u;
    edge[nodes].v=v;
    edge[nodes].l=l;
    edge[nodes].c=c;
    edge[nodes].next=head[u];
    head[u]=nodes++;
}
void dfs(int city,int nowlen,int nowmoney)
{
    if(nowlen>minlen)return;
    if(city==n&&nowlen<minlen&&nowmoney>=0)
    {
        minlen=nowlen;
        return;
    }
    for(int i=head[city]; i!=-1; i=edge[i].next)
    {
        int v=edge[i].v;
        int l=edge[i].l;
        int c=edge[i].c;
        if(!vis[v]&&nowmoney>=c)
        {
            vis[v]=1;
            dfs(v,nowlen+l,nowmoney-c);
            vis[v]=0;
        }
    }
    return;
}
int main()
{
    memset(head,-1,sizeof(head));
    memset(vis,0,sizeof(vis));
    nodes=0,minlen=inf;
    scanf("%d%d%d",&k,&n,&m);
    int u,v,l,c;
    while(m--)
    {
        scanf("%d%d%d%d",&u,&v,&l,&c);
        addedge(u,v,l,c);
    }
    dfs(1,0,k);
    if(minlen==inf)printf("-1\n");
    else
        printf("%d\n",minlen);
}

//1028K	32MS
#include<stdio.h>
#include<string.h>
#include<queue>
#define M 1007
using namespace std;
int head[M],nodes;
int k,n,m;
struct Q
{
    int pos,len,money;
    bool operator<(const Q t)const
    {
        return t.len<len;
    }
} ;
struct node
{
    int u,v,next,l,c;
}edge[M*M];
void addedge(int u,int v,int l,int c)
{
    edge[nodes].u=u;
    edge[nodes].v=v;
    edge[nodes].l=l;
    edge[nodes].c=c;
    edge[nodes].next=head[u];
    head[u]=nodes++;
}
int bfs(int u)
{
    priority_queue<Q>q;
    Q now,next;
    now.pos=1;
    now.len=0;
    now.money=0;
    q.push(now);
    while(!q.empty())
    {
        now=q.top();
        q.pop();
        int pos=now.pos,len=now.len,money=now.money;
        if(pos==n&&money<=k)return len;
        for(int i=head[pos];i!=-1;i=edge[i].next)
        {
            int v=edge[i].v;
            int l=edge[i].l;
            int c=edge[i].c;
            if(money+c<=k)
            {
                next.pos=v;
                next.len=len+l;
                next.money=money+c;
                q.push(next);
            }
        }
    }
    return -1;
}
int main()
{
    scanf("%d%d%d",&k,&n,&m);
    nodes=0;
    memset(head,-1,sizeof(head));
    int u,v,l,c;
    for(int i=0; i<m; i++)
    {
        scanf("%d%d%d%d",&u,&v,&l,&c);
        addedge(u,v,l,c);
    }
    int ans=bfs(1);
    printf("%d\n",ans);
}