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  1. // #pragma GCC optimize("O3", "unroll-loops")
  2. // #pragma GCC target("avx2", "bmi", "bmi2", "lzcnt", "popcnt")
  3.  
  4. #include <bits/stdc++.h>
  5. #define ldb long double
  6. //#define double ldb
  7. #define db double
  8. #define unomap unordered_map
  9. #define unoset unordered_set
  10. #define endl '\n'
  11. #define str string
  12. #define strstr stringstream
  13. #define sz(a) (int)a.size()
  14. #define ll long long
  15. #define int ll
  16. #define pii pair <int, int>
  17. #define pll pair <ll, ll>
  18. #define Unique(a) a.resize(unique(all(a)) - a.begin())
  19. #define ull unsigned long long
  20. #define fir first
  21. #define sec second
  22. #define idc cin.ignore()
  23. #define lb lower_bound
  24. #define ub upper_bound
  25. #define all(s) s.begin(), s.end()
  26. #define rall(s) s.rbegin(), s.rend()
  27. #define rev reverse
  28. #define gcd __gcd
  29. #define pushb push_back
  30. #define popb pop_back
  31. #define pushf push_front
  32. #define popf pop_front
  33. #define emp emplace
  34. #define empb emplace_back
  35. #define mul2x(a, x) a << x
  36. #define div2x(a, x) a >> x
  37. #define lcm(a, b) (a / __gcd(a, b) * b)
  38. #define log_base(x, base) log(x) / log(base)
  39. #define debug cerr<<"No errors!",exit(0);
  40. #define forw(i, a, b)  for (int i = a; i <= b; ++i)
  41. #define forw2(i, a, b) for (ll i = a; i <= b; ++i)
  42. #define fors(i, a, b)  for (int i = a; i >= b; --i)
  43. #define fors2(i, a, b) for (ll i = a; i >= b; --i)
  44. #define pqueue priority_queue
  45. #define sqrt sqrtl
  46. #define i128 __int128
  47. #define popcount __builtin_popcountll
  48. #define BIT(x, i) (((x) >> (i)) & 1)
  49. #define MASK(x) ((1LL) << (x))
  50. #define want_digit(x) cout << fixed << setprecision(x);
  51. #define excuting_time 1000.0 * clock() / CLOCKS_PER_SEC
  52. #define mapa make_pair
  53. using namespace std;
  54. const int MOD = 1e9 + 7; // 998244353;
  55. const int inf = 1e9;
  56. const ll INF = 1e18; // MASK(63) - 1
  57. const int limN = 1e3 + 5;
  58. const int limM = 1e4 + 5;
  59.  
  60. mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
  61. inline ll random(const ll &L, const ll &R) {
  62.     return uniform_int_distribution<ll> (L, R) (rng);
  63. }
  64.  
  65. template <class X, class Y>
  66. bool minimize(X &x, const Y &y) {
  67.     return x > y ? x = y, true : false;
  68. }
  69.  
  70. /* -------~~~~~~===== END OF TEMPLATE =====~~~~~~------- */
  71.  
  72. struct Edge {
  73.     int u, v, w;
  74.     Edge() {}
  75.     Edge(int _u, int _v, int _w): u(_u), v(_v), w(_w) {}
  76.     int other(int x) {
  77.         return x ^ u ^ v;
  78.     }
  79. } edge[limM];
  80.  
  81. int n, m, L, s, t, par[limN], id[limN][limN];
  82. ll d[limN];
  83. vector <int> adj[limN];
  84.  
  85. void print() {
  86.     forw (i, 1, m)
  87.         cout << edge[i].u - 1 << " " 
  88.         << edge[i].v - 1 << " " 
  89.         << (edge[i].w ? edge[i].w : INF) << endl;
  90. }
  91.  
  92. void dijkstra(bool back) {
  93.     memset(d, 0x3f, sizeof(d));
  94.     d[s] = 0; 
  95.     if (back) par[s] = -1;
  96.     #define pli pair <ll, int>
  97.     pqueue <pli, vector <pli>, greater <pli>> pq;
  98.     pq.emp(0, s);
  99.     while (!pq.empty()) {
  100.         ll dis; int u; tie(dis, u) = pq.top();
  101.         pq.pop();
  102.         if (dis > d[u]) continue;
  103.  
  104.         for (int i : adj[u]) {
  105.             int v = edge[i].other(u), w = edge[i].w;
  106.             if (minimize(d[v], dis + (!w ? 1 : w))) {
  107.                 if (back) par[v] = u;
  108.                 pq.emp(d[v], v);
  109.             }
  110.         }
  111.     }
  112. }
  113.  
  114. void solve() {
  115.     cin >> n >> m >> L >> s >> t;
  116.     ++s, ++t;
  117.     forw (i, 1, m) {
  118.         int u, v, w; cin >> u >> v >> w;
  119.         ++u, ++v;
  120.         edge[i] = Edge(u, v, w);
  121.         id[u][v] = id[v][u] = i;
  122.         if (w) 
  123.             adj[u].pushb(i), adj[v].pushb(i);
  124.     }
  125.  
  126.     dijkstra(false); // Tìm đường đi ngắn nhất nếu không đụng đến các cạnh khuyết
  127.  
  128.     if (d[t] < L) { // Đường đi ngắn nhất < L -> chẳng bao giờ tạo được cả
  129.         cout << "NO\n";
  130.         return;
  131.     }
  132.     if (d[t] == L) { // Chẳng cần thêm bớt gì, cứ thế mà in ra =D
  133.         cout << "YES\n";
  134.         print();
  135.         return;
  136.     }
  137.  
  138.     // Thêm các cạnh khuyết vô
  139.     forw (i, 1, m) if (!edge[i].w) {
  140.         adj[edge[i].u].pushb(i);
  141.         adj[edge[i].v].pushb(i);
  142.     }
  143.  
  144.     dijkstra(true);
  145.  
  146.     if (d[t] > L) {
  147.         cout << "NO\n";
  148.         return;
  149.     }
  150.  
  151.     vector <int> ans;
  152.     for (int pos = t; pos != s; pos = par[pos]) {
  153.         int i = id[pos][par[pos]];
  154.         if (!edge[i].w) ans.pushb(i);
  155.         else L -= edge[i].w;
  156.     }
  157.  
  158.     cout << "YES\n";
  159.     for (int x : ans) edge[x].w = 1, --L;
  160.     edge[ans.back()].w += L;
  161.     print();
  162. }
  163.  
  164. signed main() {
  165.     ios::sync_with_stdio(false), cin.tie(nullptr);
  166.     srand(time(NULL));
  167.     #define name "test"
  168.     if (fopen(name".INP", "r")) {
  169.         freopen(name".INP", "r", stdin);
  170.         freopen(name".OUT", "w", stdout);
  171.     }
  172.     bool testCase = false;
  173.     int numTest = 1;
  174.     // cin >> numTest;
  175.     forw (i, 1, numTest) {
  176.         if (testCase) cout << "Case #" << i << ": ";
  177.         solve();
  178.     }
  179.     return 0;
  180. }
Success #stdin #stdout 0.01s 5320KB
comments (?)
stdin
copy 
5 5 13 0 4
2 1 2
3 2 3
0 1 5
1 4 0
4 3 4
stdout
copy 
YES
2 1 2
3 2 3
0 1 5
1 4 8
4 3 4
https://ideone.com/9VOnAU
language:
C++14 (gcc 8.3)
created:
3 days ago
visibility:
public

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