Submission #250415

#	Time	Username	Problem	Language	Result	Execution time	Memory
250415		ryansee	Combo (IOI18_combo)	C++14	100 / 100	38 ms	592 KiB

combo

#include "combo.h"
#include "bits/stdc++.h"
using namespace std;

#define FAST ios_base::sync_with_stdio(false); cin.tie(0);
#define pb push_back
#define eb emplace_back
#define ins insert
#define f first
#define s second
#define cbr cerr<<"hi\n"
#define mmst(x, v) memset((x), v, sizeof ((x)))
#define siz(x) ll(x.size())
#define all(x) (x).begin(), (x).end()
#define lbd(x,y) (lower_bound(all(x),y)-x.begin())
#define ubd(x,y) (upper_bound(all(x),y)-x.begin())
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());    //can be used by calling rng() or shuffle(A, A+n, rng)
inline long long rand(long long x, long long y) { return rng() % (y+1-x) + x; } //inclusivesss
string inline to_string(char c) {string s(1,c);return s;} template<typename T> inline T gcd(T a,T b){ return a==0?llabs(b):gcd(b%a,a); }

using ll=long long; 
using ld=long double;
#define FOR(i,s,e) for(ll i=s;i<=ll(e);++i)
#define DEC(i,s,e) for(ll i=s;i>=ll(e);--i)
using pi=pair<ll,ll>; using spi=pair<ll,pi>; using dpi=pair<pi,pi>; 

#define LLINF ((long long)1e18)
#define INF int(1e9+1e6)
#define MAXN (300006)

std::string guess_sequence(int n) {
	string ans = "";
	ll val = press("AB");
	if(val>=1){
		val=press("A");
		if(val==1) ans = 'A';
		else ans = 'B';
	}else{
		val = press("X");
		if(val==1) ans = 'X';
		else ans = 'Y';
	}
	vector<string> pos;
	for(auto i:{"A","B","X","Y"}) if(ans != i) pos.eb(i);
	FOR(i,2,n-1){
		ll val=press(ans+pos[0]+pos[0]+ans+pos[0]+pos[1]+ans+pos[0]+pos[2]+ans+pos[1]+to_string(ans[0]));
		if(val == ans.size() + 2) ans += pos[0];
		else if(val == ans.size() + 1) ans += pos[1];
		else ans += pos[2];
	}
	if(n>1){
		ll val=press(ans+pos[0]+ans+pos[1]);
		if(val==ans.size()+1){
			ll val=press(ans+pos[0]);
			if(val==ans.size()+1)ans+=pos[0];
			else ans+=pos[1];
		}else{
			ans+=pos[2];
		}
	}
	return ans;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:47:10: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |   if(val == ans.size() + 2) ans += pos[0];
      |      ~~~~^~~~~~~~~~~~~~~~~
combo.cpp:48:15: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |   else if(val == ans.size() + 1) ans += pos[1];
      |           ~~~~^~~~~~~~~~~~~~~~~
combo.cpp:53:9: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |   if(val==ans.size()+1){
      |      ~~~^~~~~~~~~~~~~~
combo.cpp:55:10: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |    if(val==ans.size()+1)ans+=pos[0];
      |       ~~~^~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 95 / 95