Prime Cuts || UVA Solution

#include <bits/stdc++.h>
#define max 9000
#define pb push_back
#define pairs pair<int, int>
#define vi vector<int>
#define vb vector<bool>
#define vii vector<pairs>
#define lb lower_bound
#define ub upper_bound
#define lli long long int
#define endl '\n'
using namespace std;

bool isPrime[max];
vi Prime;
vi output;

void sieve() {
    memset(isPrime, true, sizeof(isPrime));     // first all odd number's prime

    isPrime[0] = 0;

    // Sieve
    for (int i = 2; i * i <= max; i++) {
        if(isPrime[i]) {
            for (int j = i * i; j <= max; j += i) {
                isPrime[j] = 0;
            }
        }
    }
}


int main() {
#ifndef Niloy
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    sieve();
    for (int i = 0; i <= max; i++) {
        if(isPrime[i] == 1) {
            Prime.push_back(i);
        }
    }

    int n, c, length;

    while(cin >> n >> c) {
        output.clear();
        length = 0;
        cout << n << " " << c << ":";
        for (int i = 0; i < n; i++) {
            if(Prime[i] <= n) {
                output.push_back(Prime[i]);
                length++;
            }
        }
        int mid = middle(length);

        mid += 1;
        cout << mid << " " << length << endl;
        if(length < 2 * c) {
            for (int i = 0; i < output.size(); i++) {
                cout << " " <<  output[i];
            }
        } else if(length % 2 == 0) {
            int b = c - 1;
            cout << b << endl;
            int low = mid - b;
            int high = mid + c;
            cout << low << " " << high << endl;
            for (int i = low - 2; i < high - 1; i++) {
                cout << " " << output[i];
            }
        } else {
            int b = c - 1;
            int low = mid - b;
            int high = mid + b;
            for (int i = low - 1; i < high; i++)
                cout << " " << output[i];
        }

        cout << endl << endl;
    }

    return 0;
}