Submission #639297

#	Time	Username	Problem	Language	Result	Execution time	Memory
639297		_fractal	Rack (eJOI19_rack)	C++14	40 / 100	1 ms	336 KiB

rack

/**
 *	author:	 fractal
 *	timus: 	 288481RF
**/

#include <bits/stdc++.h>
using namespace std;

#define F first
#define S second 
#define mp make_pair
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define speed ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define sz(x) (int)x.size()
#define len(x) (int)strlen(x)
#define all(x) x.begin(), x.end()
#define debug cerr << "OK\n";
#define ub upper_bound
#define lb lower_bound 
#define make_unique(x) sort(all(x)), x.erase(unique(all(x)), x.end())

mt19937 bruh(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rofl(chrono::steady_clock::now().time_since_epoch().count());

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef set<int> si;
typedef set<ll> sll;
typedef set<pii> spii;
typedef set<pll> spll;
typedef multiset <int> msi;
typedef multiset <ll> msll;
typedef map <int, int> mi;
typedef map <ll, ll> mll;

const int N = 1e6 + 2;
const int M = 1e5;
const int mod = 1e9 + 7;
const int inf = 2e9 + 3;
const ll INF = 1e18;
const ld pi2 = 2.0 * 3.141592653589793;
const ld pi = 3.141592653589793;
const ld eps = 1e-12;

const int dx[4] = {1, -1, 0, 0};
const int dy[4] = {0, 0, -1, 1};

#ifndef PC
    #define gcd __gcd
#endif

void files(string s = "main") {
    #ifndef PC
        freopen((s + ".in").c_str(), "r", stdin);
        freopen((s + ".out").c_str(), "w", stdout);
    #endif
}

int add(int a, int b) {
    if (a + b < 0) return a + b + mod;
    if (a + b >= mod) return a + b - mod;
    return a + b;		
}

int mul(int a, int b) {
    return a * 1LL * b % mod;
}

int binpow(int a, int n) {
    int ret = 1;
    while (n) {
        if (n & 1) ret = mul(ret, a);
        a = mul(a, a);
        n >>= 1;
    }
    return ret;
}

ll n, k, ans, pw[N];

int main() {
    speed;
    cin >> n >> k;
    pw[0] = 1;
    for (int i = 1; i <= n; ++i)
        pw[i] = mul(pw[i - 1], 2);
    k = k - 1;
    for (int i = 0; i < n; ++i) {
        if ((k >> i) & 1)
            ans = add(ans, pw[n - i - 1]);
    }
    ans = add(ans, 1);
    cout << ans << '\n';
    
}

Compilation message (stderr)

rack.cpp: In function 'void files(std::string)':
rack.cpp:64:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |         freopen((s + ".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
rack.cpp:65:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |         freopen((s + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 0 / 60