Submission #1257488

#	Time	Username	Problem	Language	Result	Execution time	Memory
1257488		MercubytheFirst	Island Hopping (JOI24_island)	C++20	65 / 100	3 ms	416 KiB

island

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

struct DSU
{
    vector<int> dsu;
    DSU(int n) : dsu(n+1, -1) { }
    int get(int x) {
        if(dsu[x] < 0) {
            return x;
        }
        return get(dsu[x]);
    }
    bool merge(int x, int y) { // merge x to y
        x = get(x), y = get(y);
        if(x == y) {
            return false;
        }
        dsu[y] += dsu[x];
        dsu[x] = y;
        return true;
    }
};

void my_assert(bool x) {
    if(!x) {
        while(true) { }
    }
}

void solve(int N, int L) {
    vector<int> by_one {1}, order(N+1, -1);
    order[1] = 0;
    for(int i = 1; i < N; ++i) {
        by_one.push_back(query(1, i));
        // cerr << "Got: " << 1 << ' ' << i << ' ' << by_one.back() << '\n';
        order[by_one.back()] = i;
    }
    for(int i = 1; i <= N; ++i) {
        // cerr << order[i] << " \n"[i == N];
    }
    vector<int> par(N+1, -1);
    DSU dsu(N);
    for(int i = 2; i <= N; ++i) {
        int cnt = 1;
        while(par[i] == -1) {
            const int x = query(i, cnt);
            // cerr << "Got: " << i << ' ' << cnt << ' ' << x << '\n';
            if(order[x] < order[i]) {
                // assert(dsu.merge(i, x));
                dsu.merge(i, x);
                par[i] = x;
            }
            else {
                // assert(dsu.merge(x, i));
                dsu.merge(x, i);
                par[x] = i;
            }
            cnt++;
        }
    }
    for(int i = 2; i <= N; ++i) {
        my_assert(par[i] != -1);
        answer(i, par[i]);
    }
}

• Subtask 1: 2 / 2
• Subtask 2: 4 / 4
• Subtask 3: 0 / 7
• Subtask 4: 9 / 9
• Subtask 5: 13 / 13
• Subtask 6: 15 / 15
• Subtask 7: 22 / 22
• Subtask 8: 0 / 28