Submission #158157

#	Time	Username	Problem	Language	Result	Execution time	Memory
158157		kig9981	Highway Tolls (IOI18_highway)	C++17	0 / 100	38 ms	7672 KiB

highway

#include "highway.h"
#include <bits/stdc++.h>

using namespace std;

vector<int> adj[90000];
set<int> gv[90000];
int g[90000];

void find_pair(int N, vector<int> U, vector<int> V, int A, int B)
{
	int M=U.size(), sg=0, tg=0, gnum=0;
	vector<int> W(M);
	long long dist=ask(W);
	queue<int> Q;
	for(int i=0;i<M;i++) {
		adj[U[i]].push_back(V[i]);
		adj[V[i]].push_back(U[i]);
	}
	for(int i=0;i<N;i++) gv[0].insert(i);
	while(gv[sg].size()>1) {
		do {
			int c=*gv[sg].begin();
			Q.push(c);
			g[c]=++gnum;
			gv[sg].erase(c);
			gv[gnum].insert(c);
			while(!Q.empty()) {
				c=Q.front();
				Q.pop();
				for(auto n: adj[c]) if(gv[gnum].size()<gv[sg].size() && g[n]==sg) {
					g[n]=gnum;
					gv[sg].erase(n);
					gv[gnum].insert(n);
					Q.push(n);
				}
			}
		} while(gv[gnum].size()<gv[sg].size());
		if(gv[gnum].size()==1) {
			for(int i=0;i<M;i++) W[i]=g[U[i]]==gnum || g[V[i]]==gnum;
			if(ask(W)==dist+B-A) sg=gnum;
		}
		else {
			long long temp;
			for(int i=0;i<M;i++) W[i]=g[U[i]]==gnum && g[V[i]]!=gnum || g[U[i]]!=gnum && g[V[i]]==gnum;
			temp=(ask(W)-dist)/(B-A);
			if(sg==tg) {
				if(temp&1) sg=gnum;
				else if(temp) sg=tg=gnum;
			}
			else if(temp&1) sg=gnum;
		}
	}
	while(gv[tg].size()>1) {
		do {
			int c=*gv[tg].begin();
			Q.push(c);
			g[c]=++gnum;
			gv[tg].erase(c);
			gv[gnum].insert(c);
			while(!Q.empty()) {
				c=Q.front();
				Q.pop();
				for(auto n: adj[c]) if(gv[gnum].size()<gv[tg].size() && g[n]==tg) {
					g[n]=gnum;
					gv[tg].erase(n);
					gv[gnum].insert(n);
					Q.push(n);
				}
			}
		} while(gv[gnum].size()<gv[tg].size());
		if(gv[gnum].size()==1) {
			for(int i=0;i<M;i++) W[i]=g[U[i]]==gnum || g[V[i]]==gnum;
			if(ask(W)==dist+B-A) tg=gnum;
		}
		else {
			for(int i=0;i<M;i++) W[i]=g[U[i]]==gnum && g[V[i]]!=gnum || g[U[i]]!=gnum && g[V[i]]==gnum;
			if((ask(W)-dist)/(B-A)&1) tg=gnum;
		}
	}
	answer(*gv[sg].begin(),*gv[tg].begin());
}

Compilation message (stderr)

highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:45:44: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    for(int i=0;i<M;i++) W[i]=g[U[i]]==gnum && g[V[i]]!=gnum || g[U[i]]!=gnum && g[V[i]]==gnum;
                              ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
highway.cpp:77:44: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    for(int i=0;i<M;i++) W[i]=g[U[i]]==gnum && g[V[i]]!=gnum || g[U[i]]!=gnum && g[V[i]]==gnum;
                              ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~

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