Submission #1232369

#	Time	Username	Problem	Language	Result	Execution time	Memory
1232369		hainam2k9	Magneti (COCI21_magneti)	C++20	110 / 110	34 ms	12616 KiB

Main

#include <bits/stdc++.h>
#define tt cin.tie(0), cout.tie(0), ios_base::sync_with_stdio(0)
#define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
#define ll long long
#define ull unsigned long long
#define i128 __int128
#define db long double
#define sz(a) ((int)(a).size())
#define pb emplace_back
#define pf emplace_front
#define pob pop_back
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define ins emplace
#define mp make_pair
using namespace std;
const int MOD = 1e9+7, MAXN = 1e4+55;
const string NAME = "";
int n,l,a[55],dp[55][55][MAXN],rs=0;
int fact[MAXN]={1,1},inv[MAXN]={1,1};
void add(int& a, int b){
    a+=b;
    if(a>=MOD) a-=MOD;
}
int modpow(int a, int b){
    if(b==0) return 1;
    ll half=modpow(a,b>>1);
    half=(half*half)%MOD;
    if(b&1) return (half*a)%MOD;
    return half;
}
ll C(int n, int k){
    return 1ll*fact[n]*(1ll*inv[k]*inv[n-k]%MOD)%MOD;
}
int main()
{
    tt;
    if(fopen((NAME + ".INP").c_str(), "r")) fo;
    for(int i = 2; i<=1e4+50; ++i)
        fact[i]=1ll*fact[i-1]*i%MOD, inv[i]=modpow(fact[i],MOD-2);
    cin >> n >> l;
    for(int i = 1; i<=n; ++i)
        cin >> a[i];
    sort(a+1,a+n+1);
    dp[0][0][0]=1;
    for(int i = 0; i<n; ++i)
        for(int j = 0; j<=i; ++j)
            for(int k = 0; k<l; ++k){
                if(dp[i][j][k]==0) continue;
                add(dp[i+1][j+1][k],1ll*(j+1)*dp[i][j][k]%MOD);
                if(j>=1&&k+a[i+1]<l) add(dp[i+1][j][k+a[i+1]],2ll*j*dp[i][j][k]%MOD);
                if(j>=2&&k+2*a[i+1]<l) add(dp[i+1][j-1][k+2*a[i+1]],1ll*(j-1)*dp[i][j][k]%MOD);
            }
    for(int i = 0; i<l; ++i)
        add(rs,dp[n][1][i]*C(l-i+n-1,n)%MOD);
    cout << rs;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:3:19: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:41:45: note: in expansion of macro 'fo'
   41 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~
Main.cpp:3:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |                                                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:41:45: note: in expansion of macro 'fo'
   41 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 30 / 30
• Subtask 4: 50 / 50