Submission #496634

#	Time	Username	Problem	Language	Result	Execution time	Memory
496634		JovanB	Magneti (COCI21_magneti)	C++17	110 / 110	182 ms	54520 KiB

Main

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

using ll = long long;
using ld = long double;

const int MOD = 1000000007;
const int N = 50;
const int LEN = 10000;

int add(int a, int b){ a += b; if(a >= MOD) a -= MOD; return a;}
int mul(int a, int b){ return (1LL*a*b)%MOD; }

int a[55];
int dp[55][55][LEN+5];

int main(){
    ios_base::sync_with_stdio(false), cin.tie(0);
    cout.precision(10);
    cout << fixed;

    int n, len;
    cin >> n >> len;
    for(int i=1; i<=n; i++) cin >> a[i];
    for(int i=1; i<=n; i++) a[i]--;
    sort(a+1, a+1+n);
    reverse(a+1, a+1+n);
    dp[0][2][0] = 1;
    for(int i=1; i<=n; i++){
        for(int k=1; k<=i+2; k++){
            int dva = 0, ddva = 0;
            int jedan = 0, jjedan = 0;
            for(int t=1; t<=len; t++){
                /// spaja dva
                ddva = add(ddva, dp[i-1][k+1][t-1]);
                dva = add(dva, ddva);
                dp[i][k][t] = add(dp[i][k][t], mul(k, dva));
                /// pored jednog
                if(t-1-a[i] >= 0) jjedan = add(jjedan, dp[i-1][k][t-1-a[i]]);
                dp[i][k][t] = add(dp[i][k][t], mul(2*k-2, jjedan));
                /// sam
                if(k >= 2 && t-1-2*a[i] >= 0) dp[i][k][t] = add(dp[i][k][t], mul(k-2, dp[i-1][k-1][t-1-2*a[i]]));
            }
        }
    }
    cout << dp[n][1][len] << "\n";
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:32:17: warning: unused variable 'jedan' [-Wunused-variable]
   32 |             int jedan = 0, jjedan = 0;
      |                 ^~~~~

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