Submission #207361

#	Time	Username	Problem	Language	Result	Execution time	Memory
207361		balbit	Split the Attractions (IOI19_split)	C++14	0 / 100	87 ms	6136 KiB

split

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define pb push_back
#define SZ(x) (int)((x).size())
#define ALL(x) x.begin(),x.end()

#define pii pair<int, int>
#define f first
#define s second

#ifdef BALBIT
#define bug(...) cerr<<"#"<<__LINE__<<": "<<#__VA_ARGS__<<" = ", _do(__VA_ARGS__)
template<typename T> void _do(T &&x) {cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T &&x, S&&...y) {cerr<<x<<", "; _do(y...);}
#define IOS()
#else
#define IOS() ios::sync_with_stdio(0), cin.tie(0)
#define endl '\n'
#define bug(...)
#endif // BALBIT

const int maxn = 2505;

vector<pii> g[maxn];
vector<int> ret;
vector<int> Cols = {1,2,3};
int sz[maxn];
int pa[maxn];
bool seen[maxn], ok[maxn*4];
int A, B;
void dfs(int v, int p = -1) {
    sz[v] = 1;
    pa[v] = p;
    seen[v] = 1;
    for (pii u : g[v]) {
        if (!seen[u.f]) {
            ok[u.s] = 1;
            dfs(u.f,v);
            sz[v] += sz[u.f];
        }
    }
}
void dc(int v, int p, int c) {
    if (c == Cols[1] && B==0) return;
    if (c == Cols[0] && A==0) return;
    ret[v] = c;
    if (c == Cols[1]) {
        --B;
    }
    if (c == Cols[0]) {
        --A;
    }
    for (pii u : g[v]) {
        if ((c!=Cols[0] || ok[u.s]) && ret[u.f]==0) {
            dc(u.f,v,c);
        }
    }
}
void fs(int n, int a, int b, int c, int start) {

    fill(ALL(ret),0);
    memset(seen,0,sizeof seen);
    memset(ok,0,sizeof ok);
    vector<int> ss = {a,b,c};

    sort(ALL(Cols),[&](int x, int y){return ss[x-1] < ss[y-1];});
    sort(ALL(ss));
    A = ss[0], B = ss[1];

    dfs(start,-1);
    int st = -1;
    for (int i = 0; i<n; i++) {
        if (sz[i] >= A && n-sz[i] >= B) {
            st = i; break;
        }
        if (sz[i] >= B && n-sz[i] >= A) {
            swap(A,B);
            swap(Cols[0], Cols[1]);
            st = i; break;
        }
    }
    if (st == -1) return;
    bug(st);
    dc(st,pa[st],Cols[0]);
    dc(pa[st],st,Cols[1]);
    for (int i = 0; i<n; i++) if (ret[i]==0)ret[i] = Cols[2];
}
vector<int> find_split(int n, int a, int b, int c, vector<int> p, vector<int> q) {
    srand(time(0));
    int m = p.size();
    for (int i = 1; i<m; i++) {
        int j = rand() % (i+1);
        swap(p[i], p[j]);
        swap(q[i], q[j]);
    }
    ret.resize(n,0);
    int iter = 0;
    for (int i = 0; i<m; i++) {
        g[p[i]].pb({q[i],iter++});
        g[q[i]].pb({p[i],iter++});
    }
    for (int i = 0; i<n; i++) {
        fs(n,a,b,c,i);
        if (ret[0] != 0) {
            return ret;
        }
    }
    return ret;
}
#ifdef BALBIT
signed main(){
    IOS();
    vector<int> ro = (find_split(6, 3, 1, 2, {0, 1, 2, 3, 4}, {1, 2, 3, 4, 5}));
    for (int x : ro) cerr<<x<<' ';
}
#endif

• Subtask 1: 0 / 7
• Subtask 2: 0 / 11
• Subtask 3: 0 / 22
• Subtask 4: 0 / 24
• Subtask 5: 0 / 36