poj 1724 ROADS 最短路

 1 #include <iostream>
 2 #include <vector>
 3 #include <cstdio>
 4 #include <cstring>
 5 #include <algorithm>
 6 #include <cmath>
 7 #include <map>
 8 #include <set>
 9 #include <string>
10 #include <queue>
11 using namespace std;
12 #define pb(x) push_back(x)
13 #define ll long long
14 #define mk(x, y) make_pair(x, y)
15 #define lson l, m, rt<<1
16 #define mem(a) memset(a, 0, sizeof(a))
17 #define rson m+1, r, rt<<1|1
18 #define mem1(a) memset(a, -1, sizeof(a))
19 #define mem2(a) memset(a, 0x3f, sizeof(a))
20 #define rep(i, a, n) for(int i = a; i<n; i++)
21 #define ull unsigned long long
22 typedef pair<int, int> pll;
23 const double PI = acos(-1.0);
24 const double eps = 1e-8;
25 const int mod = 1e9+7;
26 const int inf = 1061109567;
27 const int dir[][2] = { {-1, 0}, {1, 0}, {0, -1}, {0, 1} };
28 const int maxn = 1e5+5;
29 int head[maxn], k, n, num, dis[105][105];
30 struct node
31 {
32     int to, nextt, cost, d;
33 }e[maxn*2];
34 void init() {
35     num = 0;
36     mem1(head);
37 }
38 void add(int u, int v, int cost, int d) {
39     e[num].to = v;
40     e[num].nextt = head[u];
41     e[num].cost = cost;
42     e[num].d = d;
43     head[u] = num++;
44 }
45 struct ee
46 {
47     int u, d, cost;
48     bool operator < (ee a)const
49     {
50         if(d == a.d)
51             return cost>a.cost;
52         return d>a.d;
53     }
54     ee(){}
55     ee(int u, int d, int cost):u(u), d(d), cost(cost){}
56 };
57 int dij() {
58     priority_queue <ee> q;
59     mem2(dis);
60     dis[1][0] = 0;
61     q.push(ee(1, 0, 0));
62     while(!q.empty()) {
63         ee tmp = q.top(); q.pop();
64         if(tmp.u == n)
65             return tmp.d;
66         for(int i = head[tmp.u]; ~i; i = e[i].nextt) {
67             int v = e[i].to;
68             if(dis[v][tmp.cost+e[i].cost]>tmp.d+e[i].d) {
69                 if(tmp.cost+e[i].cost<=k) {
70                     q.push(ee(v, tmp.d+e[i].d, tmp.cost+e[i].cost));
71                     dis[v][tmp.cost+e[i].cost] = tmp.d+e[i].d;
72                 }
73             }
74         }
75     }
76     return -1;
77 }
78 int main()
79 {
80     int m, u, v, w, c;
81     while(cin>>k) {
82         cin>>n>>m;
83         init();
84         while(m--) {
85             scanf("%d%d%d%d", &u, &v, &w, &c);
86             add(u, v, c, w);
87         }
88         int ans = dij();
89         printf("%d\n", ans);
90     }
91     return 0;
92 }