1 #include<iostream>
2 #include<stdio.h>
3 #define MAXN 1005
4 #define inf 10000000
5 using namespace std;
6 int _m[MAXN][MAXN];
7 int dij[MAXN];
8 void Dijkstra(int m,int s);
9 int main()
10 {
11 //freopen("acm.acm","r",stdin);
12 int t;
13 int n;
14 int i;
15 int j;
16 int u;
17 int v;
18 int value;
19 cin>>t>>n;
20 for(i = 0; i < MAXN; ++ i)
21 {
22 for(j = 0; j < MAXN; ++ j)
23 {
24 _m[i][j] = inf;
25 // _m[j][i] = inf;
26 }
27 }
28 for(i = 0; i < t; ++ i)
29 {
30 cin>>u>>v>>value;
31 -- u;
32 -- v;
33 if(_m[u][v] > value)
34 {
35 _m[u][v] = value;
36 _m[v][u] = value;
37 }
38 }
39 //cout<<">>>>>>>>>"<<endl;
40 Dijkstra(n,n-1);
41 // for(i = 0; i < n; ++ i)
42 // {
43 cout<<dij[0]<<endl;
44 // }
45 }
46
47 void Dijkstra(int m,int s)
48 {
49 int i;
50 int j;
51 int min;
52 int * mark = new int[m];
53 memset(mark,0,m*sizeof(int));
54 memset(dij,-1,sizeof(dij));
55 dij[s] = 0;
56 mark[s] = 1;
57 int x;
58 int k;
59 min = -1;
60 for(i = 0; i < m; ++ i)
61 {
62 if(_m[s][i] != inf)
63 dij[i] = _m[s][i];
64 // cout<<"090900999 "<<dij[i]<<endl;
65 }
66 //for(i = 0; i < m; ++ i)
67 // {
68 // cout<<" dij "<<dij[i];
69 // }
70 for(k = 0; k < m; k++)
71 {
72 min = -1;
73 for(j = 0; j < m; j++)
74 {
75 if(mark[j] == 0 && dij[j] > 0)
76 {
77 if(dij[j] < min || min < 0)
78 {
79 min = dij[j];
80 x = j;
81 }
82 }
83 }
84
85 mark[x] = 1;
86 // cout<<dij[x]<<"min"<<endl;
87
88 // cout<<"00000000000000"<<endl;
89 for(i = 0; i < m; ++ i)
90 {
91 if(mark[i] == 0 && _m[x][i] != inf)
92 {
93
94 if(dij[i] < 0 || dij[x] + _m[x][i] < dij[i])
95 {
96 dij[i] = dij[x] + _m[x][i];
97 }
98 }
99 }
100 }
101 delete []mark;
102 }
