Submission #472355

#	Time	Username	Problem	Language	Result	Execution time	Memory
472355		elgamalsalman	Toll (BOI17_toll)	C++14	10 / 100	67 ms	8516 KiB

toll

#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second

typedef long long ll;
typedef pair<ll, ll> ii;
typedef vector<ll> vi;
typedef vector<ii> vii;
typedef vector<vii> vvii;

ll k, n, m, o, dp[50050];
vvii  adj;

void getToll(ll u) {
  //cerr << "// getToll(" << u << ", " << v << ")\n";
  if (dp[u] != -1) return;

  //if (u == 1) cerr << "// check1\n";

  ll minToll = 1e10;
  for (ii edge : adj[u]) {
    //if (u == 1) cerr << "// check2 {" << edge.fi << ", " << edge.se << "}\n";
    getToll(edge.fi);
    ll currToll = dp[edge.fi] + edge.se;
    if (currToll < minToll) minToll = currToll;
  }

  dp[u] = minToll;
  //cerr << "// " <<  dp[u] << '\n';
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  cin >> k >> n >> m >> o;
  adj.assign(n + 20, vii());
  for (ll i = 0; i < m; i++) {
    ll a, b, t;
    cin >> a >> b >> t;
    adj[b].push_back({a, t});
  }

  memset(dp, -1, sizeof dp);
  dp[0] = 0;
  for (int i = 0; i < n; i++) getToll(i);

  for (ll i = 0; i < o; i++) {
    ll a, b;
    cin >> a >> b;
    cout << (dp[b] >= 1e10 ? -1 : dp[b]) << '\n';
  }
}

• Subtask 1: 0 / 7
• Subtask 2: 10 / 10
• Subtask 3: 0 / 8
• Subtask 4: 0 / 31
• Subtask 5: 0 / 44