Submission #576128

#	Time	Username	Problem	Language	Result	Execution time	Memory
576128		MadokaMagicaFan	Connecting Supertrees (IOI20_supertrees)	C++14	75 / 100	199 ms	22232 KiB

supertrees

#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using vi = vector<int>;
using pi = pair<int,int>;

#define all(v)          v.begin(),v.end()
#define sort(v)         sort(all(v))
#define endl            '\n'
#define forn(i,n)       for(int i = 0; i < n; ++i)
#define forbe(i,b,e)    for(int i = b; i < e; ++i)
#define forr(i,n)       for(int i = n-1; i >= 0; --i)
#define sz(v)           ((int)v.size())
#define pb              push_back
#define f               first
#define s               second

void build(vector<vi> b);

const int N = 1e3;
int par[N];
int lst[N];
int siz[N];

vi adj[N];

int getp(int x) { return par[x] = (par[x] == x ? x : getp(par[x])); }
int getl(int x) { return lst[x] = (lst[x] == x ? x : getl(lst[x])); }

int uni(int a, int b) {
    a = getp(a);
    b = getp(b);
    int c = getl(a);
    int d = getl(b);
    if (a == b) return 0;

    adj[a].pb(d);
    adj[d].pb(a);

    par[a] = b;
    lst[d] = c;
    siz[b] += siz[a];
    return 1;
}

int construct(vector<vi> p) {
    int n = sz(p);

    bool t0, t1, t2;
    t0 = t1 = t2 = 0;
    int task = 0;
    forn(i,n) {
        forn(j,n) {
            if (i == j) continue;
            if (p[i][j] == 0) t0 = 1;
            if (p[i][j] == 1) t1 = 1;
            if (p[i][j] == 2) t2 = 1;
        }
    }

    if (t1 && !t2)  task = 1;
    if (t2 && !t1)  task = 2;
    if (t2 && t1)   task = 3;

    forn(i,n) par[i] = i;
    forn(i,n) lst[i] = i;
    forn(i,n) siz[i] = 1;

    vector<vi> ans(n);
    forn(i,n)
        ans[i].assign(n,0);
    if (task < 3) {
        forn(i,n) {
            forn(j,n) {
                if (i == j) continue;

                if (p[i][j])
                    uni(i,j);
            }
        }

        forn(i,n) {
            forn(j,n) {
                if (i == j) continue;

                if (p[i][j] == 0 && getp(i) == getp(j))
                    return 0;
            }
        }


        if (task == 2) {
            forn (i, n) {
                if (getp(i) != i) continue;
                if (siz[i] == 2) return 0;
                if (siz[i] == 1) continue;
                adj[i].pb(getl(i));
                adj[getl(i)].pb(i);
            }
        }
    } else {
        forn(i,n) {
            forn(j,n) {
                if (i == j) continue;
                if (p[i][j] == 1) uni(i,j);
            }
        }

        forn(i,n) {
            if (getp(i) != i) continue;
            lst[i] = i;
            siz[i] = 1;
        }

        forn(i,n) {
            forn(j,n) {
                if (i == j) continue;
                if (p[i][j] == 2) uni(i,j);
            }
        }

        forn (i, n) {
            if (getp(i) != i) continue;
            if (siz[i] == 2) return 0;
            if (siz[i] == 1) continue;
            adj[i].pb(getl(i));
            adj[getl(i)].pb(i);
        }
    }

    forn (i,n) {
        for (int u : adj[i])
            ans[i][u] = 1;
    }

    build(ans);

    return 1;
}

#ifdef ONPC
void build(vector<vi> b) {
    
}

void solve() {
}

int main() {
//    freopen("in", "r", stdin);
//    ios_base::sync_with_stdio(0);cin.tie(0);
    solve();
}
#endif

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:51:10: warning: variable 't0' set but not used [-Wunused-but-set-variable]
   51 |     bool t0, t1, t2;
      |          ^~

• Subtask 1: 11 / 11
• Subtask 2: 10 / 10
• Subtask 3: 19 / 19
• Subtask 4: 35 / 35
• Subtask 5: 0 / 21
• Subtask 6: 0 / 4