Submission #1252130

#	Time	Username	Problem	Language	Result	Execution time	Memory
1252130		anasszakar	Kangaroo (CEOI16_kangaroo)	C++20	0 / 100	0 ms	320 KiB

kangaroo

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")
using namespace std;
using ll = long long;
const ll INF = INT_MAX;
#define DBG cout << "# yay!" << endl;
// #define DBG

// todo: stop doing this
#define int long long
#define uchar unsigned char
#define FOR(i, a, b) for(int i = a ; i <= b ; i++)
#define ROF(i, a, b) for(int i = a ; i >= b ; i--)
#define FORK(i, a, b, k) for(int i = a ; i <= b ; i += k)
#define ROFK(i, a, b, k) for(int i = a ; i >= b ; i -= k)
#define vi vector<int>
#define pb push_back
#define ins insert
#define mpi map<int, int>
#define ALL(d) d.begin(), d.end()
#define F first
#define S second

using pr = pair<int, int>;
int binpown(int a, int b, int m) {
    int res = 1;
    while(b > 0) {
        if(b&1) res = (res*a) % m;
        a = (a*a) % m;
        b >>= 1;
    }

    return res % m;
}
 
// int invp(int v, int m) {
//     return binpowm(v, MOD-2, MOD);
// }

// int ask(int a, int b) {
//     int k;
//     cout << "? " << a << " " << b << endl << flush;
//     cin >> k;
//     return k;
// }

int _lcm(int a, int b) {
    return a * b / __gcd(a, b);
}

int chmin(uchar a, uchar b) {
    if(a > b) return b;
    else return a;
}

int ask(int a, int b) {
    a++;
    b++;
    int k;
    cout << "? " << a << " " << b << endl;
    cin >> k;
    return k;
}


int dis(int a, int b, int c, int d) {
    return (a-b)*(a-b) + (c-d)*(c-d);
}

int inv(int a, int m) {
  return a <= 1 ? a : m - (long long)(m/a) * inv(m % a, m) % m;
}

// check for 3 comps
struct DSU {
    vector<int> par, sz;
    DSU(int n) {
        par.resize(n+1);
        sz.resize(n+1, 1);
        // ecnt.resize(n+1, 0);
        FOR(i, 0, n) par[i] = i;
    }

    int pfind(int v) {
        if(v == par[v]) return v;
        else return par[v] = pfind(par[v]);
    }

    void sunion(int a, int b) {
        a = pfind(a);
        b = pfind(b);
        if(a == b) return;
        if(sz[a] > sz[b]) swap(a, b);
        par[a] = b;
        sz[b] += sz[a];
        // ecnt[b] += ecnt[a] + 1;
        // return 1;
    }
};

const ll MOD = 1e9 + 7;
void solve() {
    int n, cs, cf;
    cout << binpown(2, n-2, MOD);
}

signed main() {
    // ios::sync_with_stdio(false);
    // cin.tie(nullptr);
    freopen("kangaroo.in", "r", stdin);
    freopen("kangaroo.out", "w", stdout);
    int t = 1;
    // int t; cin >> t;
    while(t--) solve();
}

Compilation message (stderr)

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:111:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  111 |     freopen("kangaroo.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
kangaroo.cpp:112:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  112 |     freopen("kangaroo.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 6
• Subtask 2: 0 / 30
• Subtask 3: 0 / 15
• Subtask 4: 0 / 49