Submission #1082054

#	Time	Username	Problem	Language	Result	Execution time	Memory
1082054		GrindMachine	Handcrafted Gift (IOI20_gift)	C++17	100 / 100	413 ms	52380 KiB

gift

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

#include "gift.h"

struct DSU {
    vector<int> par, rankk, siz;

    DSU() {

    }

    DSU(int n) {
        init(n);
    }

    void init(int n) {
        par = vector<int>(n + 1);
        rankk = vector<int>(n + 1);
        siz = vector<int>(n + 1);
        rep(i, n + 1) create(i);
    }

    void create(int u) {
        par[u] = u;
        rankk[u] = 0;
        siz[u] = 1;
    }

    int find(int u) {
        if (u == par[u]) return u;
        else return par[u] = find(par[u]);
    }

    bool same(int u, int v) {
        return find(u) == find(v);
    }

    void merge(int u, int v) {
        u = find(u), v = find(v);
        if (u == v) return;

        if (rankk[u] == rankk[v]) rankk[u]++;
        if (rankk[u] < rankk[v]) swap(u, v);

        par[v] = u;
        siz[u] += siz[v];
    }
};

int construct(int n, int m, std::vector<int> L, std::vector<int> R, std::vector<int> X) {
    DSU dsu(n);
    set<pii> st;
    rep(i,n) st.insert({i,i});

    rep(i,m){
        int l = L[i], r = R[i], x = X[i];
        if(x == 2) conts;

        auto it = st.lower_bound({l+1,-1});
        assert(it != st.begin());
        it--;

        auto [lx,rx] = *it;
        vector<pii> todel;
        todel.pb(*it);
        it++;

        for(; it != st.end(); ++it){
            auto [lxx,rxx] = *it;
            if(lxx > r) break;
            amax(rx,rxx);
            todel.pb(*it);
        }

        trav(p,todel) st.erase(p);
        st.insert({lx,rx});
    }

    for(auto [l,r] : st){
        for(int i = l; i < r; ++i){
            dsu.merge(i,i+1);
        }
    }

    rep(i,m){
        int l = L[i], r = R[i], x = X[i];
        if(x == 2){
            if(dsu.same(l,r)){
                return 0;
            }
        }
    }

    vector<int> a(n);
    a[0] = 0;
    rep1(i,n-1){
        if(dsu.find(i) != dsu.find(i-1)){
            a[i] = a[i-1]^1;
        }
        else{
            a[i] = a[i-1];
        }
    }

    string s = "";
    rep(i,n){
        if(!a[i]) s.pb('R');
        else s.pb('B'); 
    }

    craft(s);
    return 1;

    // std::string s(n, 'R');
    // craft(s);
    // return 1;
}

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 20 / 20
• Subtask 4: 25 / 25
• Subtask 5: 30 / 30