Submission #354268

#	Time	Username	Problem	Language	Result	Execution time	Memory
354268		ryansee	Comparing Plants (IOI20_plants)	C++14	14 / 100	663 ms	4460 KiB

plants

#include "plants.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>; 
 
long long LLINF = 1e18;
int INF = 1e9+1e6;
#define MAXN (5002)
 
int n, start, k;
ll A[MAXN];
bitset<MAXN> gone;
inline ll cy(ll x) {
	x %= n, x += n, x %= n; return x;
}
vector<int> v[2][MAXN];
bitset<MAXN> reach[2][MAXN];

void init(int K, std::vector<int> r) { k=K;
	n=r.size(); if(n>5000) return;
	
	while(1) {
		start = -1;
		FOR(i,0,n-1) if(!gone[i] && r[i] == 0) {
			DEC(jj,i-1,i-k+1) {
				int j = (jj + n) % n;
				if(!gone[j] && r[j] == 0) goto no;
			}
			start = i;
			break;
			no:;
		}
		if(start == -1) break;
		
		FOR(i,start+1,start+k-1) if(!gone[i%n]) {
			A[i%n]=max(A[i%n], A[start]+1);
		}
		
		DEC(i,start-1,start-k+1) if(!gone[(i+n)%n]) {
			A[(i+n)%n] = max(A[(i+n)%n], A[start]+1), -- r[(i+n)%n];
		}
		gone[start] = 1;
	}
	// FOR(i,0,n-1) assert(r[i]==0);
	
	if(n <= 300) {
		FOR(i,0,n-1) {
			ll sm = -LLINF, pos=-1;
			FOR(jj,i+1,i+k-1) { int j=cy(jj);
				if(A[i] > A[j]) {
					if(A[j] > sm) sm = A[j], pos = j;
				} else {
					v[1][j].eb(i);
				}
			}
			if(~pos) v[0][i].eb(pos);
		}
		ll co=0;
		function<void(ll,ll)>dfs=[&](ll x,ll o){
			if(reach[co][o][x]) return;
			reach[co][o][x]=1;
			for(auto i:v[co][x]) dfs(i, o);
		};
		FOR(i,0,n-1) dfs(i, i);
		co = 1;
		FOR(i,0,n-1) dfs(i, i);
	}
}
int compare_plants(int x, int y) {
	if(n > 5000) return 0;
	if(min(y-x, n-y+x) < k || n > 300 || reach[0][x][y] || reach[0][y][x] || reach[1][x][y] || reach[1][y][x]) return A[x] < A[y] ? 1 : -1;
	else return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 14 / 14
• Subtask 3: 0 / 13
• Subtask 4: 0 / 17
• Subtask 5: 0 / 11
• Subtask 6: 0 / 15
• Subtask 7: 0 / 25