CSES - Datatähti 2021 loppu - Results
Submission details
Task:Kolmijako
Sender:Mahtimursu
Submission time:2021-01-23 19:07:43 +0200
Language:C++ (C++11)
Status:READY
Result:22
Feedback
groupverdictscore
#1ACCEPTED22
#20
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
#10ACCEPTED0.21 s2details
#11ACCEPTED0.20 s2details
#12ACCEPTED0.01 s2details
#13--2details
#140.01 s2details
#15ACCEPTED0.01 s2details

Code

#include <bits/stdc++.h>
 
typedef long long ll;
 
#define M 1000000007
#define N (1 << 18)
 
using namespace std;
 
int ans[101];
int n;
ll sum;
 
void brute(int cn) {
    if (cn == n) {
        int sums[3] = {0};
 
        for (int i = 0; i < n; ++i) {
            sums[ans[i] - 1] += i + 1;
        }
        ll ts = 0;
        for (int i = 0; i < 3; ++i) {
            ts += sums[i];
        }
        //if (ts != sum) cout << "ERR";
        //cout << sums[0] << ", " << sums[1] << ", " << sums[2] << endl;
        int t = sum / 3;
        if (sums[0] == t - 1 && sums[1] == t && sums[2] == t + 1) {
            for (int i = 0; i < n; ++i) {
                cout << ans[i] << " ";
            }
            cout << "\n";
            //exit(0);
        }
    } else {
        ans[cn] = 1;
        brute(cn + 1);
        ans[cn] = 2;
        brute(cn + 1);
        ans[cn] = 3;
        brute(cn + 1);
    }
}
 
void send(int i) {
    if (i == n) {
        int sums[3] = {0};
 
        for (int i = 0; i < n; ++i) {
            sums[ans[i] - 1] += i + 1;
        }
        ll ts = 0;
        for (int i = 0; i < 3; ++i) {
            ts += sums[i];
        }
        //if (ts != sum) cout << "ERR";
        //cout << sums[0] << ", " << sums[1] << ", " << sums[2] << endl;
        int t = sum;
        if (sums[0] == t - 1 && sums[1] == t && sums[2] == t + 1) {
            for (int i = 0; i < n; ++i) {
                cout << ans[i] << " ";
            }
            cout << "\n";
            exit(0);
        }
    } else {
        if (ans[i] == 1) {
            send(i + 1);
        } else {
            ans[i] = 2;
            send(i + 1);
            ans[i] = 3;
            send(i + 1);
        }
    }
}
 
void solve() {
    // lisätään ykköseen paljon
    sum /= 3;
    for (int mx = 0; mx < n - 2; mx++) {
        //cout << mx << endl;
        for (int i = 0; i < n; ++i) {
            ans[i] = 0;
        }
        ll one = 0;
        for (int i = 0; i <= mx; ++i) {
            ans[i] = 1;
            one += i + 1;
        }
        ll req = sum - one - 1;
        //cout << req << endl;
        if ((req <= mx || req > n) && req != 0) {
            continue;
        }
        //cout << "h" << endl;
        if (req != 0)
            ans[req - 1] = 1;
        send(mx);
        /*ll two = 0;
        ll tre = 0;
 
        for (int i = n - 1; i >= 0; --i) {
            if (ans[i] != 0) continue;
            if (two < tre) {
                ans[i] = 2;
                two += i + 1;
            } else {
                ans[i] = 3;
                tre += i + 1;
            }
        } 
        cout << two << ", " << tre << endl;
        if (two == sum && tre == sum + 1) {
            for (int i = 0; i < n; ++i) {
                cout << ans[i] << " ";
            }
            cout << "\n";
            exit(0);
        }*/
    }
}
 
int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cin >> n;
    sum = n * (n + 1) / 2;
	if (sum % 3 != 0) {
        cout << "IMPOSSIBLE";
        return 0;
    }
    solve();
    //brute(0);
 
	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
1 3 1 3 2 

Test 4

Group: 1, 2

Verdict: ACCEPTED

input
6

correct output
1 3 2 2 1 3 

user output
1 3 2 2 1 3 

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
1 1 2 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
1 1 1 2 2 2 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
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ...

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
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ...
Truncated

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
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ...
Truncated

Test 12

Group: 2

Verdict: ACCEPTED

input
97

correct output
IMPOSSIBLE

user output
IMPOSSIBLE

Test 13

Group: 2

Verdict:

input
98

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

user output
(empty)

Test 14

Group: 2

Verdict:

input
99

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

user output
(empty)

Test 15

Group: 2

Verdict: ACCEPTED

input
100

correct output
IMPOSSIBLE

user output
IMPOSSIBLE