Submission #450612

#	Time	Username	Problem	Language	Result	Execution time	Memory
450612		czhang2718	Toll (BOI17_toll)	C++14	7 / 100	303 ms	28716 KiB

toll

#include<bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for(int i=a; i<=b; i++)
#define trav(x, a) for(auto &x:a)
#define all(x) x.begin(), x.end()
#define f first
#define s second
#define nl '\n'
#define pb push_back
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef long long ll;

int n, m, k, q;
vector<pii> adj[50006];
vector<pii> radj[50006];
int lx[10006];
int rx[10006];
ll ans[10006];
map<pii, int> edge;

vector<vector<ll>> calc(int l, int r, vi &qu){
  vector<vector<ll>> vec(k*(r-l+1), vector<ll>(2*k));
  if(r-l==1){
    rep(i, 0, k-1){
      rep(j, 0, k-1){
        int t=edge[{l*k+i, r*k+j}];
        vec[i][k+j]=vec[k+j][i]=(t?t:1e10);
      }
    }
    return vec;
  }
  int m=(l+r)/2;
  vi lq, rq;
  trav(i, qu){
    if(rx[i]/k<m) lq.pb(i);
    if(lx[i]/k>m) rq.pb(i);
  }
  vector<vector<ll>> lvec=calc(l, m, lq);
  vector<vector<ll>> rvec=calc(m, r, rq);

  trav(i, qu){
    if(rx[i]/k<m || lx[i]/k>m) continue;
    if(rx[i]/k==m){
      ans[i]=lvec[lx[i]-l*k][k+rx[i]%k]; continue;
    }
    if(lx[i]/k==m){
      ans[i]=rvec[rx[i]-m*k][lx[i]%k]; continue;
    }
    ans[i]=1e10;
    rep(j, 0, k-1){
      ans[i]=min(ans[i], lvec[lx[i]-l*k][k+j]+rvec[rx[i]-m*k][j]);
    }
  }

  rep(i, l*k, m*k+k-1){
    rep(j, 0, k-1){
      vec[i-l*k][j]=lvec[i-l*k][j];
    }
  }
  rep(i, m*k, r*k+k-1){
    rep(j, k, 2*k-1){
      vec[i-l*k][j]=rvec[i-m*k][j];
    }
  }

  rep(i, (m+1)*k, r*k+k-1){
    rep(j, 0, k-1){
      vec[i-l*k][j]=1e10; 
      trav(p, radj[i]) vec[i-l*k][j]=min(vec[i-l*k][j], vec[p.f-l*k][j]+p.s);
    }
  }

  for(int i=m*k-1; i>=l*k; i--){
    rep(j, 0, k-1){
      vec[i-l*k][j+k]=1e10;
      trav(p, adj[i]) vec[i-l*k][j+k]=min(vec[i-l*k][j+k], vec[p.f-l*k][j+k]+p.s);
    }
  }
  return vec;
}

int main(){
  cin.tie(0)->sync_with_stdio(0);
  // freopen("input.txt", "r", stdin);
  // freopen("output.txt", "w", stdout);

  cin >> k >> n >> m >> q;
  rep(i, 1, m){
    int a, b, t; cin >> a >> b >> t;
    adj[a].pb({b, t});
    radj[b].pb({a, t});
    edge[{a, b}]=edge[{b, a}]=t;
  }

  vi qu;
  rep(i, 1, q){
    cin >> lx[i] >> rx[i];
    qu.pb(i);
  }
  calc(0, (n-1)/k, qu);

  rep(i, 1, q) cout << (ans[i]==1e10?-1:(lx[i]/k==rx[i]/k?-1:ans[i])) << nl;
}

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