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ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#65814 | #4843. Infectious Disease | clf123456 | Compile Error | / | / | C++20 | 1.3kb | 2022-12-03 18:37:15 | 2022-12-03 18:37:19 |
Judging History
你现在查看的是最新测评结果
- [2023-08-10 23:21:45]
- System Update: QOJ starts to keep a history of the judgings of all the submissions.
- [2022-12-03 18:37:19]
- 评测
- 测评结果:Compile Error
- 用时:0ms
- 内存:0kb
- [2022-12-03 18:37:15]
- 提交
answer
#include<bits/stdc++.h>
#define int long long
using namespace std;
const int maxn=1e7+5e6;
const int mod=1e9+7;
int jc[maxn],inv[maxn],n;
unorderer_map<pair<int,int>,int>;
struct hash_map{
bool operator()(const pair<int,int>& p) const{
return p.first+mp[p.second]*maxn;
}
};
int mp[maxn];
int C(int n,int m){
return jc[n]*inv[n-m]%mod*inv[m]%mod;
}
int ksm(int x,int p,int mod){
int ans=1;
while(p){
if(p&1) ans=ans*x%mod;
x=x*x%mod;
p>>=1;
}
return ans;
}
int dfs(int x,int y){
if(x==0) return 0;
pair<int,int>t=make_pair(x,y);
if(dp.find(t)!=t.end()) return dp[t];
int r=min(2*x,n-y);
int z=min(2*y,n-y);
int sum=n-y;
int mn=max(0LL,r+z-sum);
int mx=min(r,z);
int ans=1;
int fm=ksm(C(n-y,z),mod-2,mod);
for(int i=mn;i<=mx;i++){
ans+=C(r,i)*C(n-y-r,z-i)%mod*dfs(r-i,z+y)%mod*fm%mod;
ans%=mod;
}
return dp[t]=ans;
}
void init(){
jc[0]=inv[0]=1;
for(int i=1;i<maxn;i++) jc[i]=i*jc[i-1]%mod;
inv[maxn-1]=ksm(jc[maxn-1],mod-2,mod);
for(int i=maxn-2;i>=1;i--){
inv[i]=(i+1)*inv[i+1]%mod;
}
mp[1]=0;
int base=3;
for(int i=1;;i++){
if(base>=n){
mp[n]=i;
break;
}
mp[base]=i;
//cout<<base<<" "<<mp[base]<<endl;
base*=3;
}
}
signed main(){
//memset(dp,-1,sizeof(dp));
cin>>n;
init();
int base=1;
cout<<dfs(1,1)<<endl;
return 0;
}
詳細信息
answer.code:8:1: error: ‘unorderer_map’ does not name a type 8 | unorderer_map<pair<int,int>,int>; | ^~~~~~~~~~~~~ answer.code: In member function ‘bool hash_map::operator()(const std::pair<long long int, long long int>&) const’: answer.code:11:32: error: ‘mp’ was not declared in this scope; did you mean ‘p’? 11 | return p.first+mp[p.second]*maxn; | ^~ | p answer.code: In function ‘long long int dfs(long long int, long long int)’: answer.code:30:12: error: ‘dp’ was not declared in this scope; did you mean ‘mp’? 30 | if(dp.find(t)!=t.end()) return dp[t]; | ^~ | mp answer.code:30:26: error: ‘struct std::pair<long long int, long long int>’ has no member named ‘end’ 30 | if(dp.find(t)!=t.end()) return dp[t]; | ^~~ answer.code:42:16: error: ‘dp’ was not declared in this scope; did you mean ‘mp’? 42 | return dp[t]=ans; | ^~ | mp