Submission #535847

#	Time	Username	Problem	Language	Result	Execution time	Memory
535847		new_acc	Toll (BOI17_toll)	C++14	100 / 100	264 ms	19268 KiB

toll

#include<bits/stdc++.h>
#define fi first
#define se second
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
const int N=1e5+10;
vi zap[N],war[N];
int z[N];
vector<pair<int,int> >graf[2][N];
int odl[2][N],n,m,ans[N];
void bfs(int p,bool xd,int w,int kon){
	vector<int> curr;
	curr.push_back(p);
	odl[xd][p]=0;
	while(curr.size() and w!=kon){
		vi nxt;
		for(auto v:curr){
			for(auto [u,c]:graf[xd][v]){
				if(odl[xd][u]==-1) odl[xd][u]=odl[xd][v]+c,nxt.push_back(u);
				else odl[xd][u]=min(odl[xd][u],odl[xd][v]+c);
			}
		} 
		if(xd) w--;
		else w++;
		curr=nxt;
	}
}
void dc(int p=0,int k=n/m){
	if(p==k) return;
	int sr=(p+k)>>1;
	for(auto curr:war[sr]){
		for(int i=p;i<=k;i++)
			for(auto xd:war[i]) odl[1][xd]=-1,odl[0][xd]=-1;
		bfs(curr,0,sr,k);
		bfs(curr,1,sr,p);
		for(int i=p;i<=sr;i++){
			for(auto xd:war[i]){
				for(auto u:zap[xd])
					if(z[u]/m>sr and z[u]/m<=k and odl[1][xd]!=-1 and odl[0][z[u]]!=-1) ans[u]=min(ans[u],odl[1][xd]+odl[0][z[u]]);
			}
		}
	}
	dc(p,sr),dc(sr+1,k);
}
void solve(){
	int kr,q;
	cin>>m>>n>>kr>>q;
	for(int i=1;i<=kr;i++){
		int a,b,c;
		cin>>a>>b>>c;
		graf[0][a].push_back({b,c}),graf[1][b].push_back({a,c});
	}
	for(int i=0;i<n;i++) war[i/m].push_back(i);
	for(int i=1;i<=q;i++){
		int a,b;
		cin>>a>>b;
		ans[i]=INT_MAX;
		z[i]=b,zap[a].push_back(i);
	}	
	for(int i=1;i<=n;i++) odl[0][i]=-1;
	dc();
	for(int i=1;i<=q;i++) cout<<(ans[i]==INT_MAX?-1:ans[i])<<"\n";
}
int main(){
	ios_base::sync_with_stdio(0),cin.tie(0);
	solve();
}

Compilation message (stderr)

toll.cpp: In function 'void bfs(int, bool, int, int)':
toll.cpp:20:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   20 |    for(auto [u,c]:graf[xd][v]){
      |             ^

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