Submission #1051589

#	Time	Username	Problem	Language	Result	Execution time	Memory
1051589		pcc	Comparing Plants (IOI20_plants)	C++17	14 / 100	2657 ms	121236 KiB

plants

#include "plants.h"
#include <bits/stdc++.h>
using namespace std;

#define pii pair<int,int>
#define fs first
#define sc second

const int mxn = 1e4+10;

int arr[mxn];
int N;
int K;
int perm[mxn];
int dp[mxn];
vector<int> dag[mxn];

void smaller(int a,int b){//a<b
	//cerr<<"SMALLER: "<<a<<','<<b<<endl;
	dag[a].push_back(b);
}

void calc(int id){
	fill(dp,dp+N*2,0);
	int pre = -1;
	for(int i = 0;i<N*2;i++){
		if(i)dp[i] = (arr[i-1]?dp[i-1]:0);
		dp[i]++;
		if(!arr[i]&&pre != -1&&i-pre<K)smaller(i%N,pre%N);
		if(!arr[i])pre = i;
	}
	int tar = 0;
	for(int i = 0;i<N*2;i++){
		if(!arr[i]&&dp[i]>=K)tar = i%N;
	}
	arr[tar] = arr[tar+N] = mxn*2;
	for(int i = 0;i<K;i++){
		int pre = (tar+N-i)%N;
		arr[pre]--;arr[pre+N]--;
		if(arr[pre] < N)smaller(pre,tar);
	}
	return;
}

queue<int> q;
int deg[mxn];
bitset<mxn> vis[mxn];
void TOPO(){
	for(int i = 0;i<N;i++){
		sort(dag[i].begin(),dag[i].end());
		dag[i].resize(unique(dag[i].begin(),dag[i].end())-dag[i].begin());
		for(auto nxt:dag[i])deg[nxt]++;
	}
	for(int i = 0;i<N;i++){
		vis[i][i] = 1;
		if(!deg[i])q.push(i);
	}
	while(!q.empty()){
		auto now = q.front();
		q.pop();
		for(auto nxt:dag[now]){
			deg[nxt]--;
			vis[nxt] = vis[nxt]|vis[now];
			if(!deg[nxt])q.push(nxt);
		}
	}
	/*
	cerr<<"VIS: "<<endl;
	for(int i = 0;i<N;i++){
		for(int j = 0;j<N;j++)cerr<<vis[i][j];cerr<<endl;
	}
	*/
	return;
}

void init(int k, std::vector<int> r) {
	K = k;
	N = r.size();
	for(int i = 0;i<N;i++)arr[i] = arr[i+N] = r[i];
	for(int i = N-1;i>=0;i--)calc(i);
	TOPO();
}

int compare_plants(int x, int y) {
	return (vis[x][y]?1:vis[y][x]?-1:0);
}

• 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