Advertisement
MinhNGUYEN2k4

Untitled

Mar 27th, 2021
179
0
Never
Not a member of Pastebin yet? Sign Up, it unlocks many cool features!
C++ 2.00 KB | None | 0 0
  1. //Nguyen Huu Hoang Minh
  2. #include <bits/stdc++.h>
  3. #define sz(x) int(x.size())
  4. #define all(x) x.begin(),x.end()
  5. #define reset(x) memset(x, 0,sizeof(x))
  6. #define pb push_back
  7. #define mp make_pair
  8. #define fi first
  9. #define se second
  10. #define N 100005
  11. #define remain(x) if (x > MOD) x -= MOD
  12. #define ii pair<int, int>
  13. #define iiii pair< ii , ii >
  14. #define viiii vector< iiii >
  15. #define vi vector<int>
  16. #define vii vector< ii >
  17. #define bit(x, i) (((x) >> (i)) & 1)
  18. #define Task "test"
  19. #define int long long
  20.  
  21. using namespace std;
  22.  
  23. typedef long double ld;
  24. const int inf = 1e18;
  25. const int minf = -1e10;
  26.  
  27. int n, m;
  28. vector<ii> a[N];
  29. int d[N];
  30. int trace[N];
  31.  
  32. void readfile()
  33. {
  34.     ios_base::sync_with_stdio(false);
  35.     cin.tie(0);cout.tie(0);
  36.     if (fopen(Task".inp","r"))
  37.     {
  38.         freopen(Task".inp","r",stdin);
  39.         //freopen(Task".out","w",stdout);
  40.     }
  41.     cin >> n >> m;
  42.     for(int i=1; i<=m; i++)
  43.     {
  44.         int u, v, z;
  45.         cin >> u >> v >> z;
  46.         a[u].pb(ii(v,z));
  47.         a[v].pb(ii(u,z));
  48.     }
  49. }
  50.  
  51. void dijkstra()
  52. {
  53.     priority_queue<ii, vii, greater<ii>> q;
  54.     q.push(ii(0,1));
  55.     for(int i=1; i<=n; i++) d[i] = inf;
  56.     d[1] = 0;
  57.     while (q.size())
  58.     {
  59.         int u = q.top().se;
  60.         int du = q.top().fi;
  61.         q.pop();
  62.         if (du != d[u]) continue;
  63.         for(auto i : a[u])
  64.         {
  65.             int v = i.fi;
  66.             int uv = i.se;
  67.             if (d[v] > d[u] + uv)
  68.             {
  69.                 d[v] = d[u] + uv;
  70.                 trace[v] = u;
  71.                 q.push(ii(d[v],v));
  72.             }
  73.         }
  74.     }
  75. }
  76.  
  77. void traceback()
  78. {
  79.     int s = n;
  80.     stack<int> st;
  81.     st.push(s);
  82.     while (trace[s] != 0)
  83.     {
  84.         s = trace[s];
  85.         st.push(s);
  86.     }
  87.     while (st.size())
  88.     {
  89.         cout << st.top() << ' ';
  90.         st.pop();
  91.     }
  92. }
  93.  
  94. void proc()
  95. {
  96.     dijkstra();
  97.     if (d[n]==inf) cout << -1;
  98.     else traceback();
  99. }
  100.  
  101. signed main()
  102. {
  103.     readfile();
  104.     proc();
  105.     return 0;
  106. }
  107.  
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement