// #pragma GCC optimize("O3") #include <bits/stdc++.h> using namespace std; using vi = vector<int>; using vvi = vector<vi>; using vvvi = vector<vvi>; using pii = pair<int, int>; using vii = vector<pii>; using vvii = vector<vii>; using l = long long; using vl = vector<l>; using vvl = vector<vl>; using vvvl = vector<vvl>; using pll = pair<l, l>; using vll = vector<pll>; using vvll = vector<vll>; using d = double; using vd = vector<d>; using vvd = vector<vd>; using vvvd = vector<vvd>; using ld = long double; using vld = vector<ld>; using vvld = vector<vld>; using vvvld = vector<vvld>; using vb = vector<bool>; using vvb = vector<vb>; using pbb = pair<bool, bool>; using vbb = vector<pbb>; #define ff first #define ss second #define pb push_back #define eb emplace_back #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() #define sz(x) (int)(x).size() void setIO(string name = "") { ios_base::sync_with_stdio(0); cin.tie(0); if (!name.empty()) { (void)freopen((name + ".in").c_str(), "r", stdin); (void)freopen((name + ".out").c_str(), "w", stdout); } } const ld pi = 3.14159265358979323846; const l LINF = 1e18; const l INF = 1e9; const l MOD = 1e9 + 7; // const l MOD = 998244353; const l MAXN = 2e5 + 5; void solve() { int n, m; cin >> n >> m; vvii adj(n); vvl cost(n), dest(n), rev(n); for (int i = 0; i < m; ++i) { int a, b, c; cin >> a >> b >> c; adj[--a].pb({--b, c}); cost[a].pb(c); dest[a].pb(b), rev[b].pb(a); } for (int u = 0; u < n; ++u) sort(all(cost[u])); vl dp(n, LINF), good(n, 0); vb safe(n, false); priority_queue<pll, vll, greater<pll>> q; dp[n - 1] = 0, safe[n - 1] = true, q.push({0, n - 1}); while (q.size()) { auto [cur, u] = q.top(); q.pop(); safe[u] = true; if (cur != dp[u]) continue; for (auto v : rev[u]) { if (safe[v]) continue; l k = ++good[v], deg = cost[v].size(); l forced = cost[v][deg - k]; l newcost = forced + dp[u]; if (newcost < dp[v]) dp[v] = newcost, q.push({newcost, v}); } } cout << dp[0]; } int main() { setIO(""); #ifndef ONLINE_JUDGE // setIO("filename"); #endif int t = 1; // cin >> t; while (t--) solve(); return 0; }

ferries.cpp: In function 'void setIO(std::string)':
ferries.cpp:53:22: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   53 |         (void)freopen((name + ".in").c_str(), "r", stdin);
      |               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ferries.cpp:54:22: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   54 |         (void)freopen((name + ".out").c_str(), "w", stdout);
      |               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~