Submission #826102

#	Time	Username	Problem	Language	Result	Execution time	Memory
826102		faruk	Toys (CEOI18_toy)	C++17	59 / 100	5038 ms	5120 KiB

toy

#include <bits/stdc++.h>
#define mp make_pair
#define all(a) a.begin(), a.end()

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

const int maxn = 1e6 + 2;
/*vector<int> min_prim(maxn);
vector<vector<int> > facs(maxn);

void sito() {
    for (ll i = 1; i < maxn; i++) {
        for (ll j = i; j < maxn; j += i)
            facs[j].push_back(i);
    }
}
*/
vector<int> min_prim(maxn);
 
void sito() {
    for (ll i = 2; i < maxn; i++) {
        if (min_prim[i] != 0)
            continue;
        for (ll j = i ; j < maxn; j += i)
            if (min_prim[j] == 0)  
                min_prim[j] = i;
    }
}

vector<int> facs;
void get_small_primes(int a) {
    if (a == 1)
        return;
    facs.push_back(min_prim[a]);
    get_small_primes(a / min_prim[a]);
}

vector<int> get_small_factors(int a) {
    facs = vector<int>();
    get_small_primes(a);
    vector<int> factors;
    factors.push_back(1);
    vector<int> temp;
    facs.push_back(1e9); int cnt = 0;
    for (int i = 0; i < facs.size() - 1; i++) {
        cnt++;
        if (facs[i] != facs[i + 1]) {
            int val = 1;
            for (int j = 0; j < cnt; j++) {
                val *= facs[i];
                for (int a : factors)
                    temp.push_back(a * val);
            }
            factors.insert(factors.end(), all(temp));
            temp.clear();
            cnt = 0;
        }
    }
    sort(all(factors));
    return factors;
}

vector<int> factors;
vector<int> get_big_factors(int a, int l) {
    for (int i = 1; i * i <= a and i <= l; i++) {
        if (i * i == a)
            factors.push_back(a);
        else
        {
            factors.push_back(i);
            if (a / i <= l)
                factors.push_back(a/i);
        }
    }
    sort(all(factors));
    return factors;
}

vector<bool> there(maxn);
set<int> ans;
void recur(int n, int csum, int l) {
    if (n == 1)
    {
        if (csum > maxn)
            ans.insert(csum);
        else {
            if (there[csum])   
                return;
            there[csum] = true;
        }
        return;
    }
    vector<int> factors;
    if (n < maxn)
        factors = get_small_factors(n);
    else
        factors = get_big_factors(n, l);
    for (int i = 0; i < factors.size(); i++) { // the actual factor is a and left over is n/a
        int a = factors.at(i);
        if (a > l)
            return;
        if (a == 1)
            continue;
        recur(n/a, csum + a - 1, a);
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    sito();
    int n;
    cin >> n;
    recur(n, 0, n+1);

    vector<int> anss;
    for (int i = 0; i < maxn; i++)
        if (there[i])
            anss.push_back(i);
    for (int a : ans)
        anss.push_back(a);
    cout << anss.size() << "\n";
    for (int a : anss)
        cout << a <<" ";
    cout <<"\n";
}

Compilation message (stderr)

toy.cpp: In function 'std::vector<int> get_small_factors(int)':
toy.cpp:48:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |     for (int i = 0; i < facs.size() - 1; i++) {
      |                     ~~^~~~~~~~~~~~~~~~~
toy.cpp: In function 'void recur(int, int, int)':
toy.cpp:101:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  101 |     for (int i = 0; i < factors.size(); i++) { // the actual factor is a and left over is n/a
      |                     ~~^~~~~~~~~~~~~~~~

• Subtask 1: 19 / 19
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 21