Submission #1157608

#	Time	Username	Problem	Language	Result	Execution time	Memory
1157608		ackhava	Connecting Supertrees (IOI20_supertrees)	C++20	100 / 100	126 ms	22236 KiB

supertrees

#include "supertrees.h"
#include <vector>
#include <bits/stdc++.h>
#define REP(v, i, j) for (int v = i; v != j; v++)
#define FORI(v) for (auto i : v)
#define FORJ(v) for (auto j : v)

#define OUT(v, a) \
    FORI(v)       \
    cout << i << a;
#define OUTS(v, a, b)      \
    cout << v.size() << a; \
    OUT(v, b)
#define in(a, n) \
    REP(i, 0, n) \
    cin >> a[i];

#define SORT(v) sort(begin(v), end(v))
#define REV(v) reverse(begin(v), end(v))
#define MEMSET(m) memset(m, -1, sizeof m)

#define pb push_back
#define fi first
#define se second

#define detachIO                      \
    ios_base::sync_with_stdio(false); \
    cin.tie(0);                       \
    cout.tie(0);
    
using namespace std;

template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
bool operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y) {
    if(__x.size() != __y.size()) return false;
    return std::equal(__x.begin(), __x.end(), __y.begin());
}


typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<pii, pii> piiii;

const int MOD = 1e9+7;

struct modint {
    long long val;

    modint() = default;
    modint(int _val): val(_val){}
    modint operator+(modint b){ return ((this->val + b.val)%MOD); }
    modint operator-(modint b){ return ((MOD + this->val - b.val)%MOD); }
    modint operator*(modint b){ return ((this->val * b.val)%MOD); }
    modint operator^(int a){
        if(a==0)return 1;
        if(a==1)return *this;
        return (((*this)*(*this))^(a>>1))*((*this)^(a&1)); 
    }
};

modint invert(modint a){
    return a^(MOD-2);
}

modint operator/(modint a, modint b){
    return a*invert(b);
}

struct dsu {
	vector<int> vec;
	dsu(int n){vec.resize(n+20,-1);}
	int leader(int n){return vec[n]<0?n:vec[n]=leader(vec[n]);}
	void merge(int n,int m){n=leader(n),m=leader(m);if(n==m)return;
		if(vec[n]>vec[m])swap(n,m);
		vec[n]+=vec[m];vec[m]=n;}
};

int construct(vector<vector<int>> p) {
	vector<vector<int>> ans;
	int n = p.size();
	REP(i,0,n)ans.emplace_back(),ans.back().resize(n,0);
	dsu d(n),f(n);
	REP(i,0,n){
		REP(j,0,n){
			if(i!=j&&p[i][j]==1&&(d.leader(i)!=d.leader(j))){
				ans[i][j]=ans[j][i]=1;
				// cerr<<"PRECON "<<i<<" "<<j<<endl;
				d.merge(i,j);
				f.merge(i,j);
			}
		}
	}
	vector<int> cur;
	vector<vector<int>> loops;
	set<int>acc;
	do{
		cur.clear();
		REP(i,0,n){
			if(d.leader(i)==i&&!acc.count(i)){
				if(!cur.size()||p[cur[0]][i]==2)cur.pb(i),acc.insert(i);
			}
		}
		loops.pb(cur);
	} while(cur.size());
	loops.pop_back();
	FORI(loops){
		// cerr<<"LOOP ";
		// FORJ(i)cerr<<j<<' ';
		// cerr<<endl;
		if(i.size()<=1)continue;
		if(i.size()<3)return 0;
		REP(j,1,i.size()){
			f.merge(i[j],i[j-1]);
			ans[i[j]][i[j-1]]=1;
			ans[i[j-1]][i[j]]=1;
		}
		ans[i[0]][i.back()]=1;
		ans[i.back()][i[0]]=1;
	}
	REP(i,0,n)REP(j,0,n){
		if(p[i][j]==0){
			if(f.leader(i)==f.leader(j))return 0;
		}
		if(p[i][j]==1){
			if(d.leader(i)!=d.leader(j))return 0;
		}
		if(p[i][j]==2){
			if(d.leader(i)==d.leader(j))return 0;
			if(f.leader(i)!=f.leader(j))return 0;
		}
		if(p[i][j]==3)return 0;
		// assert(p[i][j]<3);
	}
	build(ans);
	return 1;
}

• Subtask 1: 11 / 11
• Subtask 2: 10 / 10
• Subtask 3: 19 / 19
• Subtask 4: 35 / 35
• Subtask 5: 21 / 21
• Subtask 6: 4 / 4