Submission #808341

#	Time	Username	Problem	Language	Result	Execution time	Memory
808341		The_Samurai	Connecting Supertrees (IOI20_supertrees)	C++17	96 / 100	185 ms	22080 KiB

supertrees

#include "bits/stdc++.h"
#ifdef sunnatov
#include "grader.cpp"
#else
#include "supertrees.h"
#endif

using namespace std;

struct dsu {
    vector<int> p, size;

    void init(int n) {
        p.assign(n, 0);
        size.assign(n, 1);
        for (int i = 0; i < n; i++) p[i] = i;
    }

    int get(int a) {
        return p[a] == a ? a : p[a] = get(p[a]);
    }

    void add(int a, int b) {
        a = get(a);
        b = get(b);
        if (a == b) return;
        if (size[a] > size[b]) swap(a, b);
        size[b] += size[a];
        p[a] = b;
    }
};


int construct(std::vector<std::vector<int>> p) {
	int n = p.size();

    vector<vector<int>> g(n, vector<int>(n));
    dsu ds;
    ds.init(n);
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (p[i][j]) {
                ds.add(i, j);
            }
        }
    }
    vector<bool> vis(n);
    for (int _ = 0; _ < n; _++) {
        int s = -1;
        vector<int> v;
        for (int i = 0; i < n; i++) {
            if (vis[i]) continue;
            if (s == -1) s = ds.get(i);
            if (ds.get(i) != s) continue;
            v.emplace_back(i);
        }
        if (v.empty()) break;
        for (int i = 0; i < v.size(); i++) {
            for (int j = i + 1; j < v.size(); j++) {
                if (!p[v[i]][v[j]]) return 0;
            }
        }

        // something
        vector<bool> another_vis(n);
        vector<int> cycle;
        for (int x: v) {
            if (another_vis[x]) continue;
            vector<int> line;
            for (int i = 0; i < n; i++) {
                if (p[x][i] == 1) line.emplace_back(i);
            }
            for (int i = 0; i < line.size(); i++) {
                for (int j = i + 1; j < line.size(); j++) {
                    if (p[line[i]][line[j]] != 1) return 0;
                }
            }
            for (int i = 1; i < line.size(); i++) g[line[i - 1]][line[i]] = g[line[i]][line[i - 1]] = 1;
            for (int y: line) another_vis[y] = true;
            cycle.emplace_back(line[0]);
        }
        if (cycle.size() == 2) return false;
        if (cycle.size() > 2) {
            for (int i = 1; i < cycle.size(); i++) g[cycle[i - 1]][cycle[i]] = g[cycle[i]][cycle[i - 1]] = 1;
            g[cycle[0]][cycle.back()] = g[cycle.back()][cycle[0]] = 1;
        }


        for (int x: v) vis[x] = true;
    }
    build(g);

	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:58:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |         for (int i = 0; i < v.size(); i++) {
      |                         ~~^~~~~~~~~~
supertrees.cpp:59:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |             for (int j = i + 1; j < v.size(); j++) {
      |                                 ~~^~~~~~~~~~
supertrees.cpp:73:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |             for (int i = 0; i < line.size(); i++) {
      |                             ~~^~~~~~~~~~~~~
supertrees.cpp:74:39: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   74 |                 for (int j = i + 1; j < line.size(); j++) {
      |                                     ~~^~~~~~~~~~~~~
supertrees.cpp:78:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   78 |             for (int i = 1; i < line.size(); i++) g[line[i - 1]][line[i]] = g[line[i]][line[i - 1]] = 1;
      |                             ~~^~~~~~~~~~~~~
supertrees.cpp:84:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |             for (int i = 1; i < cycle.size(); i++) g[cycle[i - 1]][cycle[i]] = g[cycle[i]][cycle[i - 1]] = 1;
      |                             ~~^~~~~~~~~~~~~~

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