CSES - Datatähti Open 2021 - Results
Submission details
Task:Split in Three
Sender:stephan
Submission time:2021-01-30 04:07:57 +0200
Language:C++11
Status:READY
Result:100
Feedback
groupverdictscore
#1ACCEPTED22
#2ACCEPTED78
Test results
testverdicttimegroup
#1ACCEPTED0.01 s1, 2details
#2ACCEPTED0.01 s1, 2details
#3ACCEPTED0.01 s1, 2details
#4ACCEPTED0.01 s1, 2details
#5ACCEPTED0.01 s1, 2details
#6ACCEPTED0.01 s1, 2details
#7ACCEPTED0.01 s1, 2details
#8ACCEPTED0.01 s1, 2details
#9ACCEPTED0.01 s2details
#10ACCEPTED0.01 s2details
#11ACCEPTED0.01 s2details
#12ACCEPTED0.01 s2details
#13ACCEPTED0.01 s2details
#14ACCEPTED0.01 s2details
#15ACCEPTED0.01 s2details

Code

///By Stephan Ramirez dsramirezc@unal.edu.co
#include<bits/stdc++.h>
#define ms(a,v) memset(a,v,sizeof a)
#define ll long long
using namespace std;
int vis[200];
int n;
int sm;
int a,b,c;
int dp[102][10100];
int can(int pos, int num){
	if(num==0)
		return 1;
	if(num<0)
		return 0;
	if(pos==0)
		return 0;
	int &ans=dp[pos][num];
	if(ans!=-1)
		return ans;
	
	ans=can(pos-1,num) ;
	if(vis[pos]==-1)
		ans|= can(pos-1,num-pos);
	return ans;
}
vector<int> aux;
void backtrack(int pos,int num){
	if(num==0)
		return ;
	if(num<0)
		return ;
	if(pos==0)
		return ;
	if(can(pos-1,num)==1){
		backtrack(pos-1,num);
		return;
	}	
	aux.push_back(pos);
	backtrack(pos-1,num-pos);
}
int main(){
	ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
	#ifdef LOCAL
		freopen("in.txt","r",stdin);
		//freopen("out.txt","w",stdout)	;
	#endif
	cin>>n;
	sm=((n+1)*n)/2;
	if(sm%3!=0){
		cout<<"IMPOSSIBLE\n";
		return 0;
	}
	b=sm/3;
	a=b-1;
	c=b+1;
	int s[3]={b,a,c};
	int id[3]={2,1,3};
	ms(vis,-1);
	for(int i=0;i<3;i++){

		ms(dp,-1);
		if(can(n,s[i])==0){
			cout<<"IMPOSSIBLE\n";
			return 0;
		}
		aux.clear();
		backtrack(n,s[i]);
		for(int j: aux){
			vis[j]=id[i];
		}
	}
	for(int i=1;i<=n;i++)
		cout<<vis[i]<<" ";
	return 0;
}

Test details

Test 1

Group: 1, 2

Verdict: ACCEPTED

input
3

correct output
1 2 3 

user output
1 2 3 

Test 2

Group: 1, 2

Verdict: ACCEPTED

input
4

correct output
IMPOSSIBLE

user output
IMPOSSIBLE

Test 3

Group: 1, 2

Verdict: ACCEPTED

input
5

correct output
1 3 1 3 2 

user output
3 2 2 1 3 

Test 4

Group: 1, 2

Verdict: ACCEPTED

input
6

correct output
1 3 2 2 1 3 

user output
2 2 3 2 3 1 

Test 5

Group: 1, 2

Verdict: ACCEPTED

input
7

correct output
IMPOSSIBLE

user output
IMPOSSIBLE

Test 6

Group: 1, 2

Verdict: ACCEPTED

input
8

correct output
2 3 1 2 3 3 2 1 

user output
2 2 1 2 2 3 3 1 

Test 7

Group: 1, 2

Verdict: ACCEPTED

input
9

correct output
1 2 3 1 2 3 3 2 1 

user output
2 2 2 2 2 1 3 1 3 

Test 8

Group: 1, 2

Verdict: ACCEPTED

input
10

correct output
IMPOSSIBLE

user output
IMPOSSIBLE

Test 9

Group: 2

Verdict: ACCEPTED

input
42

correct output
1 3 2 2 1 3 1 2 3 3 2 1 1 2 3 ...

user output
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 ...

Test 10

Group: 2

Verdict: ACCEPTED

input
95

correct output
1 3 1 3 2 1 2 3 3 2 1 1 2 3 3 ...

user output
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 ...

Test 11

Group: 2

Verdict: ACCEPTED

input
96

correct output
1 3 2 2 1 3 1 2 3 3 2 1 1 2 3 ...

user output
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 ...

Test 12

Group: 2

Verdict: ACCEPTED

input
97

correct output
IMPOSSIBLE

user output
IMPOSSIBLE

Test 13

Group: 2

Verdict: ACCEPTED

input
98

correct output
2 3 1 2 3 3 2 1 1 2 3 3 2 1 1 ...

user output
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 ...

Test 14

Group: 2

Verdict: ACCEPTED

input
99

correct output
1 2 3 1 2 3 3 2 1 1 2 3 3 2 1 ...

user output
2 2 1 2 2 2 2 2 2 2 2 2 2 2 2 ...

Test 15

Group: 2

Verdict: ACCEPTED

input
100

correct output
IMPOSSIBLE

user output
IMPOSSIBLE