| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 651673 | rafatoa | Connecting Supertrees (IOI20_supertrees) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
#pragma GCC optimize ("Ofast")
#define double ld
const int inf = 2e9;
const int INF = 4e18;
#define F first
#define S second
#define vi vector<int>
#define vvi vector<vi>
#define pi pair<int, int>
#define vpi vector<pi>
#define vb vector<bool>
#define vvb vector<vb>
#define pb push_back
#define read(a) for(auto &x:a) cin >> x;
#define print(a) for(auto x:a) cout << x << " "; cout << "\n";
#define rs resize
#define as assign
#define vc vector<char>
#define vvc vector<vc>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define ppb pop_back
#define MP make_pair
#define int ll
void build(vvi b);
struct DSU{
int n;
vi link, sz;
void init(int x){
n = x;
link.resize(n); sz.resize(n);
for(int i=0; i<n; i++)
link[i] = i, sz[i] = 1;
}
int find(int x){
if(x == link[x]) return x;
return link[x] = find(link[x]);
}
bool same(int a, int b){
return find(a) == find(b);
}
void unite(int a, int b){
a = find(a), b = find(b);
if(a == b) return;
if(sz[a] < sz[b]) swap(a, b);
sz[a] += sz[b];
link[b] = a;
}
};
int construct(vvi p){
int n = p.size();
for(int i=0; i<n; i++)
for(int j=0; j<n; j++)
if(p[i][j] == 3) return 0;
vvi b(n, vi(n, 0));
DSU dsu;
dsu.init(n);
for(int i=0; i<n; i++)
for(int j=i+1; j<n; j++)
if(p[i][j] > 0) dsu.unite(i, j);
vvi comp(n);
for(int i=0; i<n; i++)
comp[dsu.find(i)].pb(i);
for(int i=0; i<n; i++)
for(int j=0; j<comp[i].size(); j++)
for(int k=j+1; k<comp[i].size(); k++)
if(p[j][k] == 0) return 0;
for(int i=0; i<n; i++){
if(comp[i].empty()) continue;
DSU dsu2;
dsu2.init(n);
for(int j=0; j<comp[i].size(); j++)
for(int k=j+1; k<comp[i].size(); k++)
if(p[j][k] == 1) dsu2.unite(j, k);
for(int j=0; j<comp[i].size(); j++)
for(int k=j+1; k<comp[i].size(); k++)
if((dsu2.same(j, k) && p[j][k] == 2) ||
(!dsu2.same(j, k) && p[j][k] == 1)) return 0;
vvi sect(n); vi lims;
for(int j=0; j<comp[i].size(); j++)
sect[dsu2.find(j)].pb(j);
for(int j=0; j<n; j++){
if(sect[j].empty()) continue;
for(int k=0; k<sect[j].size()-1; k++)
b[sect[j][k]][sect[j][k+1]] = b[sect[j][k+1]][sect[j][k]] = 1;
lims.pb(sect[j].back());
}
for(int j=0; j<lims.size()-1; j++)
b[lims[j]][lims[j+1]] = b[lims[j+1]][lims[j]] = 1;
if(lims.size() > 1) b[lims.front()][lims.back()] = b[lims.back()][lims.front()] = 1;
}
build(b);
return 1;
}