Submission #1088375

#	Time	Username	Problem	Language	Result	Execution time	Memory
1088375		steveonalex	Split the Attractions (IOI19_split)	C++17	100 / 100	92 ms	30844 KiB

split

#include <bits/stdc++.h>
#include "split.h"
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
#define block_of_code if(true)
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double cur = rngesus(0, MASK(60) - 1);
    cur /= MASK(60) - 1;
    return l + cur * (r - l);
}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }
 
const int N = 2e5 + 69;
 
namespace Sub5{
    int n, m;
    array<int, 4> cc_size;
    vector<int> graph[N], tree[N];
    int sz[N], parent[N], h[N], up[N];
    int dfs_cnt = 0;

    void construct_dfs_tree(int u, int p){
        sz[u] = 1;
        up[u] = h[u] = h[p] + 1;
        for(int v: graph[u]) {
            if (v == p) {
                p = -1;
                continue;
            }
            if (h[v] == 0){
                construct_dfs_tree(v, u);
                tree[u].push_back(v);
                sz[u] += sz[v];
            }
            else{
                minimize(up[u], h[v]);
            }
        } 
    }


    void dfs(int u, array<int, 3> &perm, vector<int> &good_vertices){
        int cnt = 0;
        for(int v: tree[u]) if (sz[v] >= cc_size[perm[0]]){
            cnt++;
            dfs(v, perm, good_vertices);
        }
        if (cnt == 0) good_vertices.push_back(u);
    }


    void find_legal(int u, int good_height, int a, int &p1, int &p2, vector<int> &balls){
        if (up[u] < good_height && p1 - sz[u] >= a){
            p1 -= sz[u];
            p2 += sz[u];
            balls.push_back(u);
            return;
        }
        for(int v: tree[u]) find_legal(v, good_height, a, p1, p2, balls);
    }

    void paint_subtree(int u, int c, vector<int> &ans){
        ans[u] = c;
        for(int v: tree[u]){
            paint_subtree(v, c, ans);
        }
    }

    void flip_cc(int u, int &cnt, vector<int> &ans){
        if (cnt == 0) return;
        cnt--;
        ans[u] *= -1;
        for(int v: graph[u]) if (ans[v] < 0 && ans[v] == -ans[u]){
            flip_cc(v, cnt, ans);
        }
    }

    vector<int> _try(array<int, 3> perm){
        vector<int> ans(n, 0);
        vector<int> good_vertices;
        dfs(0, perm, good_vertices);

        // cout << "Perm: "; printArr(perm);
        for(int u: good_vertices) if (u != 0) {
            int p1 = sz[u], p2 = n - sz[u];

            vector<int> balls;
            find_legal(u, h[u], cc_size[perm[0]], p1, p2, balls);
            if (p2 >= cc_size[perm[1]]){
                paint_subtree(0, -perm[1], ans);
                paint_subtree(u, -perm[0], ans);

                for(int v: balls) paint_subtree(v, -perm[1], ans);

                int p1 = cc_size[perm[0]], p2 = cc_size[perm[1]];
                flip_cc(0, p2, ans);
                flip_cc(u, p1, ans);
                for(int i = 0; i < n; ++i) if (ans[i] < 0) ans[i] = perm[2];
                break;
            }
        }
        return ans;
    }
 
    vector<int> solve(int _n, int a, int b, int c, vector<int> p, vector<int> q){
        cc_size = {{0, a, b, c}};
        n = _n, m = p.size();
        for(int i = 0; i<m; ++i){
            int u = p[i], v = q[i];
            graph[u].push_back(v);
            graph[v].push_back(u);
        }

        construct_dfs_tree(0, n);
        
        vector<int> ans(n, 0);
 
        array<int, 3> perm = {{1, 2, 3}};
        sort(ALL(perm), [](int x, int y){
            return cc_size[x] <  cc_size[y];
        });
        for(int i = 0; i<=1; ++i){
            if (maximize(ans, _try(perm)))
                break;
            swap(perm[0], perm[1]);
        }
        return ans;
    }
 
}
 
vector<int> find_split(int n, int a, int b, int c, vector<int> p, vector<int> q) {
    return Sub5::solve(n, a, b, c, p, q);
}
 
 
// int main(void){
//     ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
//     clock_t start = clock();
 
//     int n, m; cin >> n >> m;
//     int a, b, c; cin >> a >> b >> c;
//     vector<int> p(m), q(m);
//     for(int i= 0; i<m; ++i) cin >> p[i] >> q[i];
 
//     vector<int> ans = find_split(n, a, b, c, p, q);
//     printArr(ans); 
 
//     cerr << "Time elapsed: " << clock() - start << " ms\n";
//     return 0;
// }

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