ROADS - Roads

N cities named with numbers 1 ... N are connected with one-way roads. Each road has two parameters associated with it: the road length and the toll that needs to be paid for the road (expressed in the number of coins). Bob and Alice used to live in the city 1. After noticing that Alice was cheating in the card game they liked to play, Bob broke up with her and decided to move away - to the city N. He wants to get there as quickly as possible, but he is short on cash. We want to help Bob to find the shortest path from the city 1 to the city N that he can afford with the amount of money he has.

Input

The input begins with the number t of test cases. Then t test cases follow. The first line of the each test case contains the integer K, 0 <= K <= 10000, maximum number of coins that Bob can spend on his way. The second line contains the integer N, 2 <= N <= 100, the total number of cities. The third line contains the integer R, 1 <= R <= 10000, the total number of roads. Each of the following R lines describes one road by specifying integers S, D, L and T separated by single blank characters : S is the source city, 1 <= S <= N D is the destination city, 1 <= D <= N L is the road length, 1 <= L <= 100. T is the toll (expressed in the number of coins), 0 <= T <= 100 Notice that different roads may have the same source and destination cities.

Output

For each test case, output a single line contain the total length of the shortest path from the city 1 to the city N whose total toll is less than or equal K coins. If such path does not exist, output -1.

Example

Input:
2
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
0
4
4
1 4 5 2
1 2 1 0
2 3 1 1
3 4 1 0

Output:
11
-1

题目大意:有n个点 m条边 每条边有长度和花费两个权值。要求在花费《=k的情况下,找出从点1到点n的最短的距离。不存在输出-1

bfs+优先队列。优先队列只是优化。

/* ***********************************************
Author        :guanjun
Created Time  :2016/9/4 19:25:30
File Name     :spoj_roads.cpp
************************************************ */
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <stdio.h>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <iomanip>
#include <list>
#include <deque>
#include <stack>
#define ull unsigned long long
#define ll long long
#define mod 90001
#define INF 0x3f3f3f3f
#define maxn 10010
#define cle(a) memset(a,0,sizeof(a))
const ull inf = 1LL << 61;
const double eps=1e-5;
using namespace std;

int n,m,k;
struct Edge{
    int next,y,l,c;
}edge[maxn];
int pre[maxn],L;
void add(int u,int y,int l,int c){
    edge[L].y=y;
    edge[L].l=l;
    edge[L].c=c;
    edge[L].next=pre[u];
    pre[u]=L++;
}

struct node{
    int y,l,c;
};
struct cmp{
    bool operator()(node a,node b){
        if(a.l==b.l) return a.c>b.c;
        return a.l>b.l;
    }
};

int bfs(){
    priority_queue<node,vector<node>,cmp>q;
    q.push({1,0,0});
    while(!q.empty()){
        node u=q.top();q.pop();
        if(u.y==n){
            return u.l;
        }
        node tmp;
        //cout<<"y "<<u.y<<endl;
        for(int i=pre[u.y];i+1;i=edge[i].next){
            int y=edge[i].y;
            int c=edge[i].c;
            int l=edge[i].l;
            if(u.c+c<=k){
                tmp.y=y;
                tmp.l=u.l+l;
                tmp.c=u.c+c;
                q.push(tmp);
            }
        }
    }
    return INF;
}
int main()
{
    #ifndef ONLINE_JUDGE
    freopen("in.txt","r",stdin);
    #endif
    //freopen("out.txt","w",stdout);
    int t,x,y,z,w;
    cin>>t;
    while(t--){
        cin>>k>>n>>m;
        L=0;
        memset(pre,-1,sizeof pre);
        for(int i=1;i<=m;i++){
            scanf("%d %d %d %d",&x,&y,&z,&w);
            add(x,y,z,w);
        }
        int w=bfs();
        if(w==INF){
            puts("-1");
        }
        else cout<<w<<endl;
    }
    return 0;
}
时间: 2024-12-13 09:20:19

ROADS - Roads的相关文章

poj 3625 Building Roads 最小生成树(prime或kruskal+并查集)(算法归纳)

Time Limit:1000MS Memory Limit:65536KB 64bit IO Format:%I64d & %I64u Description Farmer John had just acquired several new farms! He wants to connect the farms with roads so that he can travel from any farm to any other farm via a sequence of roads;

ACdream 1415 Important Roads

Important Roads Special JudgeTime Limit: 20000/10000MS (Java/Others)Memory Limit: 128000/64000KB (Java/Others) Problem Description The city where Georgie lives has n junctions some of which are connected by bidirectional roads.      Every day Georgie

poj 3625 Building Roads

题目连接 http://poj.org/problem?id=3625 Building Roads Description Farmer John had just acquired several new farms! He wants to connect the farms with roads so that he can travel from any farm to any other farm via a sequence of roads; roads already conn

洛谷——P2872 [USACO07DEC]道路建设Building Roads

P2872 [USACO07DEC]道路建设Building Roads 题目描述 Farmer John had just acquired several new farms! He wants to connect the farms with roads so that he can travel from any farm to any other farm via a sequence of roads; roads already connect some of the farms

建造道路 (Building Roads, USACO 2007 Dec)

题目描述 Farmer John had just acquired several new farms! He wants to connect the farms with roads so that he can travel from any farm to any other farm via a sequence of roads; roads already connect some of the farms. Each of the N (1 ≤ N ≤ 1,000) farms

POJ3625 Building Roads

Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 10803   Accepted: 3062 Description Farmer John had just acquired several new farms! He wants to connect the farms with roads so that he can travel from any farm to any other farm via a sequ

USACO 2007 December Contest, Silver Problem 2. Building Roads Kruskal最小生成树算法

PROBLEM: (ENGLISH VERSION) Farmer John had just acquired several new farms! He wants to connect the farms with roads so that he can travel from any farm to any other farm via a sequence of roads; roads already connect some of the farms. Each of the N

POJ 2421 Constructing Roads 修建道路 最小生成树 Kruskal算法

题目链接:POJ 2421 Constructing Roads 修建道路 Constructing Roads Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 19698   Accepted: 8221 Description There are N villages, which are numbered from 1 to N, and you should build some roads such that e

Constructing Roads In JGShining&#39;s Kingdom HDU - 1025

JGShining's kingdom consists of 2n(n is no more than 500,000) small cities which are located in two parallel lines. Half of these cities are rich in resource (we call them rich cities) while the others are short of resource (we call them poor cities)