제출 #1331929

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1331929		vahagng	캥거루 (CEOI16_kangaroo)	C++20	100 / 100	23 ms	23120 KiB

kangaroo

//----------vahagng----------//
#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
using namespace std;
// using namespace __gnu_pbds;

// template <class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif

void print(long long t) { cerr << t; }
void print(int t) { cerr << t; }
void print(string t) { cerr << t; }
void print(char t) { cerr << t; }
void print(double t) { cerr << t; }
void print(long double t) { cerr << t; }
void print(unsigned long long t) { cerr << t; }

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(T v[], V n) { cerr << "["; for (int i = 0; i < n; i++) { cerr << v[i] << " "; } cerr << "]"; }
template <class T, class V> void print(pair <T, V> p) { cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}"; }
template <class T> void print(vector <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T> void print(set <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T> void print(multiset <T> v) { cerr << "[ "; for (T i : v) { print(i); cerr << " "; } cerr << "]"; }
template <class T, class V> void print(map <T, V> v) { cerr << "[ "; for (auto i : v) { print(i); cerr << " "; } cerr << "]"; }

#define ll long long
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define ld long double
#define sz(v) v.size()
#define endl '\n'

const ll inf = 2e18, mod = 1e9 + 7, mod2 = 998244353;

void SetIO(string str = "") {
    if (str != "") {
        freopen((str + ".in").c_str(), "r", stdin);
        freopen((str + ".out").c_str(), "w", stdout);
    }
    else {
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    }
}

void FastIO() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
}

const int N = 2e5 + 10, M = 1e7 + 10;

mt19937 rnd(chrono::system_clock::now().time_since_epoch().count());

ll binpow(ll a, ll b) {
    ll res = 1;
    while (b) {
        if (b & 1) {
            res = (res * a) % mod2;
        }
        b >>= 1;
        a = (a * a) % mod2;
    }
    return res;
}

ll n, a, b, dp[2002][2002];

void solve(int tc) {
    cin >> n >> a >> b;
    dp[1][1] = 1;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= i; j++) {
            if (i + 1 == a || i + 1 == b) {
                dp[i + 1][j + 1] = (dp[i + 1][j + 1] + dp[i][j]) % mod;
                dp[i + 1][j] = (dp[i + 1][j] + dp[i][j]) % mod;
            }
            else {
                dp[i + 1][j + 1] = (dp[i + 1][j + 1] + ((j + 1 - (i + 1 > a) - (i + 1 > b)) * dp[i][j]) % mod) % mod;
                if (j >= 2) {
                    dp[i + 1][j - 1] = (dp[i + 1][j - 1] + ((j - 1) * dp[i][j]) % mod) % mod;
                }
            }
        }
    }
    cout << dp[n][1] << endl;
    return;
}

void precalc() {
    
}

int main() {
    // SetIO("teamwork");
    FastIO();
    int test_case = 1;
    // cin >> test_case;
    precalc();
    int cnt = 1;
    while (test_case--) {
        solve(cnt++);
    }
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

kangaroo.cpp: In function 'void SetIO(std::string)':
kangaroo.cpp:47:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |         freopen((str + ".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kangaroo.cpp:48:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |         freopen((str + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kangaroo.cpp:51:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         freopen("input.txt", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
kangaroo.cpp:52:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |         freopen("output.txt", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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