Sponsors

Codeforces Round #429 (Div. 2), problem: (E) On the Bench Solution In C/C++

#include<bits/stdc++.h>
#define ll long long int
#define LL long long int
#define ULL unsigned long long int
#define sf(a) scanf(“%d”,&a)
#define sl(a) scanf(“%lld”,&a)
#define fr first
#define sc second
#define pii pair<int,int>
#define pll pair<LL,LL>
#define vi vector<int>
#define vll vector<LL>
#define vpii vector<pii>
#define rep1(a,b) for(int a=1;a<=b;a++)
#define rep2(a,b) for(int a=0;a<b;a++)
#define CLR(a,b) memset(a,b,sizeof(a))
#define Clear(a,b) memset(a,b,sizeof(a))
#define pb push_back
#define mp make_pair
#define mod 1000000007
#define LSOne(S) (S&(-S))
#define all(a) a.begin(),a.end()
#define Prime 31
using namespace std;
#define maxn 200100
#define INF 1ll<<62
#define mMax 20005
#define nMax 2505
#define SZ(a) a.size()
LL ar1[305];
class UnionFind { // OOP style
private:
vi p, rank, setSize; // remember: vi is vector<int>
int numSets;
public:
UnionFind(int N) {
setSize.assign(N, 1); numSets = N; rank.assign(N, 0);
p.assign(N, 0); for (int i = 0; i < N; i++) p[i] = i; }
int findSet(int i) { return (p[i] == i) ? i : (p[i] = findSet(p[i])); }
bool isSameSet(int i, int j) { return findSet(i) == findSet(j); }
void unionSet(int i, int j) {
if (!isSameSet(i, j)) { numSets–;
int x = findSet(i), y = findSet(j);
// rank is used to keep the tree short
if (rank[x] > rank[y]) { p[y] = x; setSize[x] += setSize[y]; }
else { p[x] = y; setSize[y] += setSize[x];
if (rank[x] == rank[y]) rank[y]++; } } }
int numDisjointSets() { return numSets; }
int sizeOfSet(int i) { return setSize[findSet(i)]; }
};
LL bigmod(LL a,LL p)
{
if(p==1) return a%mod;
if(p%2) return (a*bigmod(a,p-1))%mod;
LL c=bigmod(a,p/2);
return (c*c)%mod;
}
LL factn[1000],invfactn[1000];
LL factm[1000],invfactm[1000];
void init(int n)
{
factn[0]=1;
invfactn[0]=1;
for(LL i=1;i<=n;i++) factn[i]=(factn[i-1]*i)%mod;
for(LL i=1;i<=n;i++) invfactn[i]=(invfactn[i-1]*bigmod(i,mod-2))%mod;
return ;
}
void init2(int n)
{
factm[0]=1;
invfactm[0]=1;
for(LL i=1;i<=n;i++) factm[i]=(factm[i-1]*i)%mod;
for(LL i=1;i<=n;i++) invfactm[i]=(invfactm[i-1]*bigmod(i,mod-2))%mod;
return ;
}
LL nCr(int n,int r)
{
if(n<0) return 0;
if(n<r) return 0;
LL res=(invfactn[n-r]*invfactn[r])%mod;
res=(res*factn[n])%mod;
return res;
}
LL nPr2(int n,int r)
{
LL res=(invfactm[n-r])%mod;
res=(res*factm[n])%mod;
return res;
}
vi vec1;
LL dp[305][305];
LL call(int i,int bad,int n,int total)
{
if(i==n) return (bad==0);
LL &ret=dp[i][bad];
if(ret!=-1) return ret;
ret=0;
int cur_total=total+vec1[i];
int gaps=total+1;
for(int split=1;split<= min(gaps,vec1[i]);split++)
{
for(int chosen_bad_gap=0;chosen_bad_gap<=min(bad,split);chosen_bad_gap++)
{
int good_gaps=gaps-chosen_bad_gap;
int new_bad= bad-chosen_bad_gap+vec1[i]-split;
int good_splits=split-chosen_bad_gap;
LL temp=1;
temp= (nCr(vec1[i]-1,split-1)*factn[vec1[i]])%mod;
temp = (temp*nCr(bad,chosen_bad_gap))%mod;
temp = (temp* nCr(gaps-bad,good_splits) )%mod;
temp = (temp* call(i+1,new_bad,n,total+vec1[i]))%mod;
ret = (ret+temp)%mod;
}
}
return ret;
}
int main()
{
#ifdef shakil
freopen(“input.txt”,”r”,stdin);
//freopen(“output.txt”,”w”,stdout);
#endif
map<int,int> Map;
int n,k;
cin>>n;
for(int i=0;i<n;i++) {scanf(“%d”,&ar1[i]);Map[ar1[i]]++;}
UnionFind uf(n);
for(int i=0;i<n;i++)
for(int j=0;j<n;j++)
{
double a=sqrt(ar1[i]*ar1[j]);
if(floor(a)==ceil(a))
uf.unionSet(i,j);
}
init(n+2);
int s=uf.numDisjointSets();
set<int> S;
for(int i=0;i<n;i++) S.insert(uf.findSet(i));
vi x;
for(set<int>::iterator it=S.begin();it!=S.end();it++) x.pb(*it);
for(int i=0;i<x.size();i++) vec1.pb(uf.sizeOfSet(x[i]));
CLR(dp,-1);
LL res=call(0,0,x.size(),0);
//for(map<int,int>::iterator it=Map.begin();it!=Map.end();it++) res= (res*invfactn[it->sc])%mod;
printf(“%lld\n”,res);
return 0;
}

Changpeng Zhao’s memoir is...

Changpeng Zhao’s "Freedom of Money": A Roadmap for the...

AL East Injury Notes:...

AL East Injury Crisis: Key Updates on Springer, Holliday,...

Hacks Recap: New York...

Hacks Recap: Deborah Vance and the Little Debbies Take...

Why is Tesla Up...

Understanding the Recent $28 Surge in Tesla StockTesla investors...

Candace Owens Responds to...

Candace Owens Criticizes Erika Kirk Over TPUSA Event Cancellation The...

Passive component demand splits...

The Shift in Passive Component Demand: AI and Automotive...

Changpeng Zhao’s memoir is key to understanding the future of crypto

Changpeng Zhao’s "Freedom of Money": A Roadmap for the Future of CryptoIn the rapidly evolving landscape of digital assets, few figures loom as large...

AL East Injury Notes: Yesavage, Springer, Holliday, Uceta

AL East Injury Crisis: Key Updates on Springer, Holliday, and Yesavage The American League East has long been regarded as the most grueling division in...

Hacks Recap: New York or Nowhere

Hacks Recap: Deborah Vance and the Little Debbies Take on New York The latest episode of Hacks, titled "New York or Nowhere," brings a fresh...

Why is Tesla Up $28

Understanding the Recent $28 Surge in Tesla StockTesla investors have plenty to celebrate as the company’s stock recently witnessed a significant $28 jump. This...

Candace Owens Responds to Erika Kirk Pulling Out of Event With VP JD Vance

Candace Owens Criticizes Erika Kirk Over TPUSA Event Cancellation The political commentary landscape is heating up following a public disagreement between two prominent figures. Candace...

Passive component demand splits in 2026; AI and autos hold firm

The Shift in Passive Component Demand: AI and Automotive Drive 2026 Growth As we approach 2026, the global passive components sector is witnessing a significant...

Cuba’s president warns US against attacking island or trying to depose him

Cuba's President Issues Stern Warning to United States Over Regime Change Threats In a recent and forceful address, Cuban President Miguel Diaz-Canel has sent a...

Samsung’s compact speakers bring wireless home theater sound anywhere

Samsung Redefines Home Audio with Compact Wireless Speakers Samsung has officially released its highly anticipated line of compact lifestyle speakers, bringing a new level of...

Bihar hostel horror: Canteen guard held for rape, murder of minor student, ‘claims he acted to defame institution’

Shocking Incident: Bihar Hostel Guard Arrested for Murder and Rape of MinorIn a chilling turn of events that has sparked widespread outrage across the...