Submission #472358

#	Time	Username	Problem	Language	Result	Execution time	Memory
472358		elgamalsalman	Toll (BOI17_toll)	C++14	10 / 100	3069 ms	7716 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, dp1[50050], dp2[50050];
vvii  adj;

void getToll2(ll u, ll v) {
  //cerr << "// getToll(" << u << ", " << v << ")\n";
  if (dp2[u] != -1) return;
  if (u == v) { dp2[u] = 0; return; }
  if (u/k >= v/k) { dp2[u] = 1e10; 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";
    getToll2(edge.fi, v);
    if (dp2[edge.fi] >= 1e10) continue;
    ll currToll = dp2[edge.fi] + edge.se;
    if (currToll < minToll) minToll = currToll;
  }

  dp2[u] = minToll;
  //cerr << "// " <<  dp2[u] << '\n';
}

void getToll1(ll u) {
  //cerr << "// getToll(" << u << ", " << v << ")\n";
  if (dp1[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";
    getToll1(edge.fi);
    ll currToll = dp1[edge.fi] + edge.se;
    if (currToll < minToll) minToll = currToll;
  }

  dp1[u] = minToll;
  //cerr << "// " <<  dp1[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(dp1, -1, sizeof dp1);
  dp1[0] = 0;
  for (int i = 0; i < n; i++) getToll1(i);

  for (ll i = 0; i < o; i++) {
    memset(dp2, -1, sizeof dp2);
    ll a, b;
    cin >> a >> b;
    if (a == 0) {
      cout << (dp1[b] >= 1e10 ? -1 : dp1[b]) << '\n';
    } else {
      getToll2(a, b);
      cout << (dp2[b] >= 1e10 ? -1 : dp2[b]) << '\n';
    }
  }
}

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