Submission #389115

#	Time	Username	Problem	Language	Result	Execution time	Memory
389115		apostoldaniel854	Connecting Supertrees (IOI20_supertrees)	C++14	100 / 100	289 ms	24064 KiB

supertrees

#include <bits/stdc++.h>

using namespace std;


//#define HOME


#ifndef HOME
#include "supertrees.h"
#endif // HOME

#ifdef HOME

static int n;
static vector<vector<int>> p;
static vector<vector<int>> b;
static bool called = false;




static void check(bool cond, string message) {
    if (!cond) {
        printf("%s\n", message.c_str());
        fclose(stdout);
        exit(0);
    }
}

void build(std::vector<std::vector<int>> _b) {
    check(!called, "build is called more than once");
    called = true;
    check((int)_b.size() == n, "Invalid number of rows in b");
    for (int i = 0; i < n; i++) {
        check((int)_b[i].size() == n, "Invalid number of columns in b");
    }
    b = _b;
}
#endif // HOME

/**
4
1 1 2 2
1 1 2 2
2 2 1 2
2 2 2 1

**/
const int max_n = 1000;
int father[1 + max_n];
int find_father (int x) {
    if (father[x] == x)
        return x;
    return father[x] = find_father (father[x]);
}

vector <vector <int>> answer;

void connect (int x, int y, bool add) {
    x = find_father (x);
    y = find_father (y);
    if (x != y) {
        father[x] = y;
        if (add)
            answer[x][y] = answer[y][x] = 1;
    }
}

int construct(std::vector<std::vector<int>> p) {
	int n = p.size();
	answer.resize (n);
	for (int i = 0; i < n; i++)
        answer[i].resize (n);
    for (int i = 0; i < n; i++)
        father[i] = i;
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++) {
            if (p[i][j] == 3)
                return 0;
            if (p[i][j] == 1)
                connect (i, j, true);
        }
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            if (find_father (i) == find_father (j) && p[i][j] != 1)
                return 0;
    vector <bool> is_root (n);
    for (int i = 0; i < n; i++)
        if (find_father (i) == i)
            is_root[i] = true;
    for (int i = 0; i < n; i++)
        father[i] = i;
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            if (is_root[i] && is_root[j] && p[i][j] == 2)
                connect (i, j, false);
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            if (i != j && find_father (i) == find_father (j) && p[i][j] != 2)
                return 0;
    for (int i = 0; i < n; i++) {
        if (find_father (i) == i) {
            vector <int> v;
            for (int j = 0; j < n; j++)
                if (find_father (j) == i)
                    v.push_back (j);
            if (v.size () == 2) return 0;
            if (v.size () >= 3) {
                for (int j = 1; j < v.size (); j++)
                    answer[v[j - 1]][v[j]] = answer[v[j]][v[j - 1]] = 1;
                answer[v[0]][v.back ()] = answer[v.back ()][v[0]] = 1;
            }
        }
    }
    build(answer);
	return 1;
}

#ifdef HOME
int main() {
    assert(scanf("%d", &n) == 1);

    p.resize(n);
    for (int i = 0; i < n; i++) {
        p[i].resize(n);
    }

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            assert(scanf("%d", &p[i][j]) == 1);
        }
    }
    fclose(stdin);

    int possible = construct(p);

    check(possible == 0 || possible == 1, "Invalid return value of construct");
    if (possible == 1) {
        check(called, "construct returned 1 without calling build");
    } else {
        check(!called, "construct called build but returned 0");
    }

    printf("%d\n", possible);
    if (possible == 1) {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                if (j) {
                    printf(" ");
                }
                printf("%d", b[i][j]);
            }
            printf("\n");
        }
    }
    fclose(stdout);
}
#endif // HOME

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:110:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  110 |                 for (int j = 1; j < v.size (); j++)
      |                                 ~~^~~~~~~~~~~

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