Submission #1224990

#	Time	Username	Problem	Language	Result	Execution time	Memory
1224990		thelegendary08	Highway Tolls (IOI18_highway)	C++20	18 / 100	267 ms	327680 KiB

highway

#include "highway.h"
#include<bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define vi vector<int>
#define vvi vector<vector<int>>
#define pii pair<int, int>
#define vpii vector<pair<int, int>>
#define vc vector<char>
#define vb vector<bool>
#define mii map<int,int>
#define f0r(i,n) for(int i=0;i<n;i++)
#define FOR(i,k,n) for(int i=k;i<n;i++)
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define in(a) int a; cin>>a
#define in2(a,b) int a,b; cin>>a>>b
#define in3(a,b,c) int a,b,c; cin>>a>>b>>c
#define in4(a,b,c,d) int a,b,c,d; cin>>a>>b>>c>>d
#define vin(v,n); vi v(n); f0r(i,n){cin>>v[i];}
#define out(a) cout<<a<<'\n'
#define out2(a,b) cout<<a<<' '<<b<<'\n'
#define out3(a,b,c) cout<<a<<' '<<b<<' '<<c<<'\n'
#define out4(a,b,c,d) cout<<a<<' '<<b<<' '<<c<<' '<<d<<'\n'
#define pout(a) cout<<a.first<<' '<<a.second<<'\n'
#define vout(v) for(auto u : v){cout<<u<<' ';} cout<<'\n'
#define dout(a) cout<<a<<' '<<#a<<'\n'
#define dout2(a,b) cout<<a<<' '<<#a<<' '<<b<<' '<<#b<<'\n'
#define yn(x); if(x){cout<<"YES"<<'\n';}else{cout<<"NO"<<'\n';}
const int leg = 1e9 + 7;
const int mod = 998244353;
using namespace std;
const int mxn = 90005;
vvi adj(mxn); 
vi dep(mxn);
vi par(mxn);
void dfs(int node, int from){
	par[node] = from;
	for(auto u : adj[node]){
		if(u != from){
			dep[u] = dep[node] + 1;
			dfs(u, node);
		}
	}
}
int n;
void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B) {
	n = N;
	f0r(i, N){
		adj[i].clear(); 
		dep[i] = 0;
		par[i] = -1;
	}
	int M = U.size();
	f0r(i, M){
		adj[U[i]].pb(V[i]);
		adj[V[i]].pb(U[i]);
	}
	dfs(0,-1);
	int mx = 0;
	f0r(i, N){
		mx = max(mx, dep[i]);
	}
	vvi deps(mx+1);
	vi edg(N, -1);
	vi cha(M);
	f0r(i, M){
		deps[max(dep[U[i]], dep[V[i]])].pb(i);
		if(dep[U[i]] > dep[V[i]]){
			cha[i] = U[i];
			edg[U[i]] = i;
		}
		else{
			cha[i] = V[i];
			edg[V[i]] = i;
		}
	}
	vi quer(n-1);
	f0r(i, n-1)quer[i] = 0;
	long long r = ask(quer);
	long long length = r / A;
	
	int lo = 1; int hi = mx;
	while(lo < hi){
		int mid = lo + (hi - lo + 1) / 2;
		vi quer(n-1);
		f0r(i, n){
			if(dep[i] >= mid){
				quer[edg[i]] = 1;
			}
		}
		long long r = ask(quer);
		if(r != length * A){
			lo = mid;
		}
		else hi = mid - 1;
	}
	
	int ld = lo; //lowest depth in path, so must be at least depth of one of A and B 
	// dout(ld);
	
	lo = 1; hi = ld;
	while(lo < hi){
		int mid = lo + (hi - lo) / 2;
		vi quer(n-1);
		FOR(i, 1, n){
			if(dep[i] <= mid){
				quer[edg[i]] = 1;
			}
		}
		long long r = ask(quer);
		if(r != length * A){
			hi = mid;
		}
		else lo = mid + 1;
	}

	int hd = lo - 1;
	// dout(hd);
	
	lo = 0; hi = deps[ld].size() - 1;
	while(lo < hi){
		int mid = lo + (hi - lo) / 2;
		vi quer(n-1);
		f0r(i, deps[ld].size()){
			if(i <= mid){
				quer[deps[ld][i]] = 1;
			}
		}
		long long r = ask(quer);
		if(r != length * A){
			hi = mid;
		}
		else{
			lo = mid + 1;
		}
	}
	// dout(lo);
	// vout(deps[ld]);
	int fi = cha[deps[ld][lo]];
	// dout(fi);
	
	int span = ld - hd;
	if(span == length){
		int se = fi;
		f0r(i, length){
			se = par[se];
		}
		answer(fi, se);
	}
	else{
		int od = length - span + hd;
		if(od == ld){
			lo++; hi = deps[ld].size() - 1; int slo = lo;
			// cout<<lo<<' '<<hi<<endl;
			
			while(lo < hi){
				int mid = lo + (hi - lo) / 2;
				vi quer(n-1);
				FOR(i, slo, deps[ld].size()){
					if(i <= mid){
						quer[deps[ld][i]] = 1;
					}
				}
				long long r = ask(quer);
				if(r != length * A){
					hi = mid;
				}
				else{
					lo = mid + 1;
				}
			}
			int se = cha[deps[ld][lo]];
			answer(fi, se);
		}
		else{
			vi bababa(n);
			int cur = fi;
			while(cur != 0){
				bababa[cur] = 1;
				cur = par[cur];
			}
			lo = 0; hi = deps[od].size() - 1;
			while(lo < hi){
				int mid = lo + (hi - lo) / 2;
				vi quer(n-1);
				f0r(i, deps[od].size()){
					if(i <= mid && bababa[cha[deps[od][i]]] == 0){
						quer[deps[od][i]] = 1;
					}
				}
				long long r = ask(quer);
				if(r != length * A){
					hi = mid;
				}
				else{
					lo = mid + 1;
				}
			}
			int se = cha[deps[od][lo]];
			// dout2(fi, se);
			answer(fi, se);
		}
	}
	
	// answer(0, 1);
	/*
	for (int j = 0; j < 50; ++j) {
	std::vector<int> w(M);
	for (int i = 0; i < M; ++i) {
	  w[i] = 0;
	}
	long long toll = ask(w);
	}
	answer(0, N - 1);
	*/
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 6 / 6
• Subtask 4: 0 / 33
• Subtask 5: 0 / 18
• Subtask 6: 0 / 31