Submission #514513

#	Time	Username	Problem	Language	Result	Execution time	Memory
514513		Killer2501	Zapina (COCI20_zapina)	C++14	110 / 110	384 ms	452 KiB

zapina

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define ull unsigned long long
#define pb push_back
#define pll pair<ll, ll>
#define pii pair<int, int>
#define fi first
#define se second
using namespace std;
const int N = 4e2+5;
const int M = 26;
const ll inf = 1e15;
const ll mod = 1e9+7;
const ld ex = 1e-9;
int n, t, k, m, d[N], lab[N];
ll ans, tong, a[N], b[N], c[N], dp[2][N][2], cnt;
string s;
struct node
{
    int x, y, val;
    int vx, vy;
    node(){}
    node(int _x, int _vx, int _y, int _vy)
    {
        x = _x;
        vx = _vx;
        y = _y;
        vy = _vy;
    }
};
ll pw(ll k, ll n)
{
    ll total = 1;
    for(; n; n >>= 1)
    {
        if(n&1)total = total * k % mod;
        k = k * k % mod;
    }
    return total;
}
ll C(ll u, ll v)
{
    if(u > v)return 0;
    return a[v] * b[u] % mod * b[v-u] % mod;
}
void add(ll& x, ll y)
{
    x += y;
    if(x >= mod)x -= mod;
}
void sol()
{
    cin >> n;
    a[0] = b[0] = 1;
    for(int i = 1; i <= n; i ++)
    {
        a[i] = a[i-1] * i % mod;
        b[i] = b[i-1] * pw(i, mod-2) % mod;
    }
    dp[0][0][0] = 1;
    for(int i = 0; i < n; i ++)
    {
        int nxt = (i&1)^1;
        memset(dp[nxt], 0, sizeof(dp[nxt]));
        for(int j = 0; j <= n; j ++)
        {
            for(int p = 0; p <= n-j; p ++)
            {
                if(p != i+1)
                {
                    add(dp[nxt][p+j][0], dp[i&1][j][0] * C(p, n-j) % mod);
                    add(dp[nxt][p+j][1], dp[i&1][j][1] * C(p, n-j) % mod);
                }
                else
                {
                    add(dp[nxt][p+j][1], dp[i&1][j][1] * C(p, n-j) % mod);
                    add(dp[nxt][p+j][1], dp[i&1][j][0] * C(p, n-j) % mod);
                }
            }
        }
    }
    cout << dp[n&1][n][1];
}
int main()
{
    cin.tie(0);
    cout.tie(0);
    ios_base::sync_with_stdio(0);
    #define task "test"
    if(fopen(task".inp", "r"))
	{
		freopen(task".inp", "r", stdin);
		freopen(task".out", "w", stdout);
    }
    int ntest = 1;
    //cin >> ntest;
    while(ntest -- > 0)
    sol();
}

Compilation message (stderr)

zapina.cpp: In function 'int main()':
zapina.cpp:93:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   93 |   freopen(task".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
zapina.cpp:94:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |   freopen(task".out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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