poj 1724ROADS（bfs和dfs做法）

 /*
 dfs比较好想，就是测试数据的问题，导致在遍历边的时候要倒着遍历才过！
 */
 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<vector>
 #include<algorithm>
 #define Max 0x3f3f3f3f
 using namespace std;

 struct node{
    int D;
    int L, T;
    node(int D, int L, int T){
       this->D=D;
       this->L=L;
       this->T=T;
    }
    node(){
    }
 };

 node v[][];
 int cnt[];
 int vis[];

 int maxCost, R, N, S, D, L, T;
 int cost, dist;

 void dfs(int cur, int d, int c){
    int i;
    if(cur == N){
        if(dist>d){
           dist=d;
           if(cost>c)  cost=c;
        }
        return ;
    }
    for(i=cnt[cur]-; i>=; --i)
       if(!vis[v[cur][i].D] &&  c+v[cur][i].T<=maxCost && d+v[cur][i].L<dist){
          vis[v[cur][i].D]=;
          dfs(v[cur][i].D, d+v[cur][i].L, c+v[cur][i].T);
          vis[v[cur][i].D]=;
       }
 }

 int main(){
    while(scanf("%d", &maxCost)!=EOF){
        scanf("%d%d", &N, &R);
        memset(cnt, , sizeof(cnt));
        while(R--){
           scanf("%d%d%d%d", &S, &D, &L, &T);
           v[S][cnt[S]++]=node(D, L, T);
        }
        cost=dist=Max;
        memset(vis, , sizeof(vis));
        dfs(, , );
        if(cost<=maxCost)
           printf("%d\n", dist);
        else printf("-1\n");
    }
    return ;
 }

 /*
   spfa + 01背包
   dist[next][j]=min(dist[cur][j-v[cur][i].T]+v[cur][i].L) j={v[cur][i].T。。。maxCost}
   一维数组表示的是城市节点，二维表示的当前费用
   dist[i][j]表示经过i城市，费用为j时总的路径长度！
 */
 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<vector>
 #include<queue>
 #include<algorithm>
 #define Max 0x3f3f3f3f
 using namespace std;

 struct node{
    int D;
    int L, T;
    node(int D, int L, int T){
       this->D=D;
       this->L=L;
       this->T=T;
    }
    node(){
    }
 };

 node v[][];
 int cnt[];
 int dist[][];
 int vis[];
 queue<int>q;
 int maxCost, R, N, S, D, L, T;

 int spfa(){
    int i;
    while(!q.empty()){
        int cur = q.front();
        q.pop();
        vis[cur]=;
        for(i=; i<cnt[cur]; ++i){
            int next=v[cur][i].D;
            for(int j=v[cur][i].T; j<=maxCost; ++j)
               if(dist[next][j]>dist[cur][j-v[cur][i].T]+v[cur][i].L){
                  dist[next][j]=dist[cur][j-v[cur][i].T]+v[cur][i].L;
                  if(!vis[next]){
                    vis[next]=;
                    q.push(next);
                  }
              }
        }
    }
 }

 void bfs(int cur){
    q.push();
    memset(dist, 0x3f, sizeof(dist));
    for(int i=; i<; ++i)
       dist[][i]=;
    vis[]=;
    spfa();
 }

 int main(){
    while(scanf("%d", &maxCost)!=EOF){
        scanf("%d%d", &N, &R);
        memset(cnt, , sizeof(cnt));
        while(R--){
           scanf("%d%d%d%d", &S, &D, &L, &T);
           v[S][cnt[S]++]=node(D, L, T);
        }
        memset(vis, , sizeof(vis));
        bfs();
        int minDist=Max;
        for(int i=; i<=maxCost; ++i)
           if(minDist>dist[N][i])
               minDist=dist[N][i];
        if(minDist!=Max)
           printf("%d\n", minDist);
        else printf("-1\n");
    }
    return ;
 }