Submission #1114270

#	Time	Username	Problem	Language	Result	Execution time	Memory
1114270		ljtunas	Zapina (COCI20_zapina)	C++14	110 / 110	210 ms	3584 KiB

zapina

#include <bits/stdc++.h>

using namespace std;

#define db  double
#define pb  push_back
#define ll  long long
#define int long long
#define ii  pair<int, int>
#define fi  first
#define se  second
#define vi  vector <int>
#define vii vector<ii>
#define sqrt sqrtl
#define FORV(v, H)     for(auto &v: H)
#define FOR(i, a, b)   for(int i=a;i<=b;++i)
#define FORD(i, a, b)  for(int i=a;i>=b;--i)
#define BIT(mask, i)   ((mask >> i) & 1LL)
#define ONBIT(mask, i) (mask bitor (1LL << i))
#define cnt_BIT(i)   __builtin_popcountll(i)

#define task "zapina"

const int MAXN = 350  + 10;
const int   oo = 1e18 + 8;
const int  MOD = 1e9 + 7;

int N;
int dp[MAXN][MAXN][2];
int GT[MAXN], CKN[MAXN][MAXN];

int Pow(int a, int n) {
    if (n == 0) return 1;
    int h = Pow(a, n / 2);
    h = (h * h) % MOD;
    if (n & 1) return (a * h) % MOD;
    return h;
}

int Ckn(int k, int n) {
    if (k > n) return 0;
    int MAU = (GT[n - k] * GT[k]) % MOD;
    int  TU = GT[n];
    return (TU * Pow(MAU, MOD - 2)) % MOD;
}

int solve(int i, int cnt, bool ok) {
    if (i > N) {
        if (cnt == 0) return ok;
        return 0;
    }
    if (~dp[i][cnt][ok])
        return dp[i][cnt][ok];
    int cur = 0;
    FOR(j, 0, cnt) {
        if (j == i)
            cur = (cur + solve(i + 1, cnt - j, 1) * CKN[j][cnt]) % MOD;
        else
            cur = (cur + solve(i + 1, cnt - j, ok) * CKN[j][cnt]) % MOD;
    }
    return dp[i][cnt][ok] = cur;
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(nullptr);
    cout.tie(nullptr);
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }


    GT[0] = 1;
    FOR(i, 1, MAXN - 5) GT[i] = (GT[i - 1] * i) % MOD;

    FOR(i, 0, MAXN) {
        FOR(j, 0, MAXN) CKN[i][j] = Ckn(i, j);
    }

    cin >> N;
    memset(dp, -1, sizeof(dp));
    cout << solve(1, N, 0);
    return 0;
}

Compilation message (stderr)

zapina.cpp: In function 'int main()':
zapina.cpp:69:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
zapina.cpp:70:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
zapina.cpp:78:35: warning: iteration 360 invokes undefined behavior [-Waggressive-loop-optimizations]
   78 |         FOR(j, 0, MAXN) CKN[i][j] = Ckn(i, j);
      |                         ~~~~~~~~~~^~~~~~~~~~~
zapina.cpp:16:37: note: within this loop
   16 | #define FOR(i, a, b)   for(int i=a;i<=b;++i)
......
   78 |         FOR(j, 0, MAXN) CKN[i][j] = Ckn(i, j);
      |             ~~~~~~~~~~               
zapina.cpp:78:9: note: in expansion of macro 'FOR'
   78 |         FOR(j, 0, MAXN) CKN[i][j] = Ckn(i, j);
      |         ^~~

• Subtask 1: 22 / 22
• Subtask 2: 33 / 33
• Subtask 3: 55 / 55