Submission #685757

#	Time	Username	Problem	Language	Result	Execution time	Memory
685757		jamezzz	Flight to the Ford (BOI22_communication)	C++17	0 / 100	128 ms	118784 KiB

communication

#include "communication.h"
#include <bits/stdc++.h>
using namespace std;
//
// --- Sample implementation for the task communication ---
//
// To compile this program with the sample grader, place:
//     communication.h communication_sample.cpp sample_grader.cpp
// in a single folder, then open the terminal in this directory (right-click onto an empty spot in the directory,
// left click on "Open in terminal") and enter e.g.:
//     g++ -std=c++17 communication_sample.cpp sample_grader.cpp
// in this folder. This will create a file a.out in the current directory which you can execute from the terminal
// as ./a.out
// See task statement or sample_grader.cpp for the input specification
//

typedef pair<int,int> ii;
typedef vector<ii> vii;
#define pb push_back
#define sz(x) (int)x.size()

int getSize(vii &v){
	int sum=0;
	for(auto[a,b]:v)sum+=b-a+1;
	return sum;
}

int inside(vii &v,int X){
	int half=getSize(v)/2;
	for(int i=0;i<sz(v);++i){
		if(half==0)break;
		auto[l,r]=v[i];
		if(r-l+1<=half){
			if(l<=X&&X<=r)return 1;
			half-=r-l+1;
		}
		else{
			if(l<=X&&X<=l+half-1)return 1;
			half=0;
		}
	}
	return 0;
}

void split(vii &v,vii &vi,vii &ve){
	int half=getSize(v)/2;
	for(int i=0;i<sz(v);++i){
		auto[l,r]=v[i];
		if(r-l+1<=half)vi.pb({l,r});
		else if(half==0)ve.pb({l,r});
		else vi.pb({l,l+half-1}),ve.pb({l+half,r});
	}
}

void encode(int N,int X){
    vii corr,wrong;
    corr.pb({1,N});
    while(sz(corr)+sz(wrong)>3){
		int res=send(inside(corr,X)||inside(wrong,X));
		vector<ii> corrI,corrE,wrongI,wrongE;
		split(corr,corrI,corrE);
		split(wrong,wrongI,wrongE);
		corr.clear();
		wrong.clear();
		if(res==1){
			for(ii x:corrI)corr.pb(x);
			for(ii x:wrongI)corr.pb(x);
			for(ii x:corrE)wrong.pb(x);
		}
		else{
			for(ii x:corrE)corr.pb(x);
			for(ii x:wrongE)corr.pb(x);
			for(ii x:corrI)wrong.pb(x);
		}
	}
	vector<int> rem;
	for(auto [l,r]:corr){
		for(int i=l;i<=r;++i)rem.pb(i);
	}
	for(auto [l,r]:wrong){
		for(int i=l;i<=r;++i)rem.pb(i);
	}
	if(X==rem[0])send(0),send(0),send(0),send(0);
	if(X==rem[1])send(1),send(1),send(0),send(0);
	if(X==rem[2])send(1),send(1),send(1),send(1);
}

ii decode(int N){
    vii corr,wrong;
    corr.pb({1,N});
    while(sz(corr)+sz(wrong)>3){
		int res=receive();
		vector<ii> corrI,corrE,wrongI,wrongE;
		split(corr,corrI,corrE);
		split(wrong,wrongI,wrongE);
		corr.clear();
		wrong.clear();
		if(res==1){
			for(ii x:corrI)corr.pb(x);
			for(ii x:wrongI)corr.pb(x);
			for(ii x:corrE)wrong.pb(x);
		}
		else{
			for(ii x:corrE)corr.pb(x);
			for(ii x:wrongE)corr.pb(x);
			for(ii x:corrI)wrong.pb(x);
		}
	}
	vector<int> rem;
	for(auto [l,r]:corr){
		for(int i=l;i<=r;++i)rem.pb(i);
	}
	for(auto [l,r]:wrong){
		for(int i=l;i<=r;++i)rem.pb(i);
	}
	int tot=0;
	for(int i=0;i<4;++i)tot+=receive();
	if(tot<=2)return {rem[0],rem[1]};
	else return {rem[1],rem[2]};
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 85