Submission #526745

#	Time	Username	Problem	Language	Result	Execution time	Memory
526745		Olympia	Connecting Supertrees (IOI20_supertrees)	C++17	11 / 100	174 ms	22140 KiB

supertrees

#include <cmath>
#include <cassert>
#include <iostream>
#include <set>
#include <climits>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <type_traits>
#include <string>
#include <queue>
#include <map>
#include "supertrees.h"

#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("Ofast")
#pragma GCC optimization ("unroll-loops")

using namespace std;

class DisjointSetUnion {
protected:
    vector<int> parent;
    vector<int> compSize;
    const int n;
    int connectedComponents;
public:
    int getConnectedComponents() const {
        return connectedComponents;
    }

public:
    DisjointSetUnion(int sz) : n(sz), connectedComponents(sz) {
        parent.resize(sz), compSize.resize(sz);
        for (int i = 0; i < n; i++) {
            parent[i] = i, compSize[i] = 1;
        }
    }

    int find_head(int x) const {
        int cur = x;
        while (cur != parent[cur]) {
            cur = parent[cur];
        }
        return cur;
    }

    void join(int x, int y) {
        x = find_head(x);
        y = find_head(y);
        if (x == y) {
            return;
        }
        if (compSize[x] > compSize[y]) {
            swap(x, y);
            //ensures that compSize[x1] <= compSize[y1]
        }
        parent[x] = y;
        compSize[y] += compSize[x];
        connectedComponents--;
    }

    bool comp(int x, int y) {
        return (find_head(x) == find_head(y));
    }
};

/*
void build (vector<vector<int>> grid) {
    for (int i = 0; i < grid.size(); i++) {
        for (int j: grid[i]) {
            cout << j << ' ';
        }
        cout << '\n';
    }
}
 */


int construct (vector<vector<int>> grid) {
    vector<vector<int>> ans(grid.size());
    for (int i = 0; i < grid.size(); i++) {
        ans[i].assign(grid[0].size(), 0);
    }
    set<int> s;
    DisjointSetUnion disjointSetUnion(grid.size());
    for (int i = 0; i < grid.size(); i++) {
        for (int j = 0; j < grid.size(); j++) {
            s.insert(grid[i][j]);
            if (grid[i][j]) {
                disjointSetUnion.join(i, j);
            }
        }
    }
    if (s.count(1) && s.size() == 1) {
        for (int i = 1; i < grid.size(); i++) {
            ans[i][0] = ans[0][i] = 1;
        }
        build(ans);
        return 1;
    }
    if (s.count(1) && s.count(0) && s.size() == 2) {
        map<int,vector<int>> myMap;
        for (int i = 0; i < grid.size(); i++) {
            myMap[disjointSetUnion.find_head(i)].push_back(i);
        }
        for (auto& p: myMap) {
            vector<int> v = p.second;
            for (int i = 1; i < (int)v.size(); i++) {
                ans[v[i - 1]][v[i]] = 1;
                ans[v[i]][v[i - 1]] = 1;
            }
        }
        build(ans);
        return 1;
    }
}

/*
int main () {
    vector<vector<int>> grid =
            {{0, 1, 0, 0}, {1, 0, 0, 0}, {0, 0, 0, 1}, {0, 0, 1, 0}};
    construct(grid);
}
 */

Compilation message (stderr)

supertrees.cpp:16: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
   16 | #pragma GCC optimization ("O3")
      | 
supertrees.cpp:17: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
   17 | #pragma GCC optimization ("Ofast")
      | 
supertrees.cpp:18: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
   18 | #pragma GCC optimization ("unroll-loops")
      | 
supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:83:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   83 |     for (int i = 0; i < grid.size(); i++) {
      |                     ~~^~~~~~~~~~~~~
supertrees.cpp:88:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   88 |     for (int i = 0; i < grid.size(); i++) {
      |                     ~~^~~~~~~~~~~~~
supertrees.cpp:89:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   89 |         for (int j = 0; j < grid.size(); j++) {
      |                         ~~^~~~~~~~~~~~~
supertrees.cpp:97:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   97 |         for (int i = 1; i < grid.size(); i++) {
      |                         ~~^~~~~~~~~~~~~
supertrees.cpp:105:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  105 |         for (int i = 0; i < grid.size(); i++) {
      |                         ~~^~~~~~~~~~~~~
supertrees.cpp:82:40: warning: control reaches end of non-void function [-Wreturn-type]
   82 |     vector<vector<int>> ans(grid.size());
      |                                        ^

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