Submission #744951

#	Time	Username	Problem	Language	Result	Execution time	Memory
744951		sword060	Magneti (COCI21_magneti)	C++17	0 / 110	1077 ms	442316 KiB

Main

#include <bits/stdc++.h>
using namespace std;
const int N=10005,M=1e9+7;
int x,k,dp[N][1<<10][11],dp2[N][51],a[N];
int rec(int i,int msk,int lst){
  if(i>k)return 0;
  if((msk^(1<<lst))==0)return k-i+1;
  if(~dp[i][msk][lst])return dp[i][msk][lst];
  int ret=rec(i+1,msk,lst)%M;
  for(int nxt=0;nxt<x;nxt++)
    if(msk&(1<<nxt))
      ret=(ret+rec(i+max(a[lst+1],a[nxt+1]),msk^(1<<lst),nxt))%M;
  return dp[i][msk][lst]=ret;
}
int rec2(int i,int j){
  if(j==0)return 1;
  if(i>k)return 0;
  if(~dp2[i][j])return dp2[i][j];
  int ret=(((rec2(i+a[1],j-1)*j)%M)+(rec2(i+1,j)%M))%M;
  return dp2[i][j]=ret;
}
int main(){
  ios::sync_with_stdio(0);cin.tie(0);
  cin>>x>>k;
  for(int i=1;i<=x;i++)cin>>a[i];
  if(x<=10){
    memset(dp,-1,sizeof(dp));
    long long sum=0;
    for(int i=0;i<x;i++)sum=(sum+rec(1,(1<<x)-1,i))%M;
    cout<<sum;
  }else{
    memset(dp2,-1,sizeof(dp2));
    cout<<rec2(1,x);
  }
  return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 30
• Subtask 4: 0 / 50