Submission #222327

#	Time	Username	Problem	Language	Result	Execution time	Memory
222327		ryansee	Table Tennis (info1cup20_tabletennis)	C++14	100 / 100	579 ms	35440 KiB

tabletennis

#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); }
 
typedef int ll; 
typedef long double ld;
#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)
typedef pair<ll,ll>pi; typedef pair<ll,pi>spi; typedef pair<pi,pi>dpi;
 
#define LLINF ((long long)1e18)
#define INF int(1e9+1e6)
#define MAXN (200006)
ll n,k,A[MAXN];
bitset<MAXN> taken;
struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }
 
    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};
unordered_map<ll,ll,custom_hash> mp;
#define gc getchar_unlocked
void in(ll&x){
	x=0;
	char ch=gc();
	while(ch<'0'||ch>'9')ch=gc();
	while(ch>='0'&&ch<='9'){
		x=(x<<3)+(x<<1)+ch-48;
		ch=gc();
	}
}
int main(){
	FAST
	in(n),in(k);
	n+=k;
	FOR(i,1,n)in(A[i]),mp[A[i]]=i;
	auto tryy=[&](ll sum){
		taken.reset();
		ll co=0,other=0,mi=0;
		FOR(i,1,n)if(!taken[i] && co<n-k && (mi==0||co+(mi-i)-((mi-i)&1)>=n-k)){
			other=mp[sum-A[i]];
			if(other>i) {
				mi=other;
				co+=2;
				taken[i]=taken[other]=1;
			}
		}else break;
		if(co==n-k)return 1;
		else return 0;
	};
	if(n<4*k){
		FOR(i,1,k+1)DEC(j,n,n-k)if(i<=j&&tryy(A[i]+A[j])){
			FOR(i,1,n)if(taken[i])cout<<A[i]<<' ';cout<<'\n';
			return 0;
		}
	}else{
		unordered_map<ll,ll,custom_hash> mp;
		FOR(i,1,2*k)DEC(j,n,n-2*k+1)++mp[A[i]+A[j]];
		for(auto i:mp)if(i.s>=k&&tryy(i.f)){
			FOR(i,1,n)if(taken[i])cout<<A[i]<<' ';cout<<'\n';
			return 0;
		}
	}
	assert(0);
}

Compilation message (stderr)

tabletennis.cpp: In function 'int main()':
tabletennis.cpp:22:20: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
 #define FOR(i,s,e) for(ll i=s;i<=ll(e);++i)
                    ^
tabletennis.cpp:77:4: note: in expansion of macro 'FOR'
    FOR(i,1,n)if(taken[i])cout<<A[i]<<' ';cout<<'\n';
    ^~~
tabletennis.cpp:77:42: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
    FOR(i,1,n)if(taken[i])cout<<A[i]<<' ';cout<<'\n';
                                          ^~~~
tabletennis.cpp:22:20: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
 #define FOR(i,s,e) for(ll i=s;i<=ll(e);++i)
                    ^
tabletennis.cpp:84:4: note: in expansion of macro 'FOR'
    FOR(i,1,n)if(taken[i])cout<<A[i]<<' ';cout<<'\n';
    ^~~
tabletennis.cpp:84:42: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
    FOR(i,1,n)if(taken[i])cout<<A[i]<<' ';cout<<'\n';
                                          ^~~~

• Subtask 1: 11 / 11
• Subtask 2: 9 / 9
• Subtask 3: 14 / 14
• Subtask 4: 15 / 15
• Subtask 5: 9 / 9
• Subtask 6: 14 / 14
• Subtask 7: 15 / 15
• Subtask 8: 13 / 13