Submission #1003359

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
1003359	2024-06-20T09:10:49 Z	toast12	Connecting Supertrees (IOI20_supertrees)	C++14	11 / 100	125 ms	24196 KB

supertrees

/*
	idea for subtask 4:
	- separate the nodes into different components according to input
	- in each component, find the nodes that require exactly one path 
	  from that node to some other node in the component
	- create a tree using these nodes
	- assign one node "root" node and create a cycle with all the 2-path
	  nodes and this node

*/

#include "supertrees.h"
#include <vector>
#include <map>
#include <iostream>
#include <set>
using namespace std;

#define sz(x) (int)x.size()

struct DSU {
	int n;
	vector<int> link, size;
	DSU(int sz) {
		n = sz;
		link.resize(sz);
		size.resize(sz);
		for (int i = 0; i < n; i++) {
			link[i] = i;
			size[i] = 1;
		}
	}
	int find(int x) {
		while (x != link[x])
			x = link[x];
		return x;
	} 
	bool same(int a, int b) {
		return find(a) == find(b);
	}
	void unite(int a, int b) {
		a = find(a);
		b = find(b);
		if (a == b)
			return;
		if (size[a] < size[b])
			swap(a, b);
		link[b] = a;
		size[a] += size[b];
	}
};

int construct(std::vector<vector<int>> p) {
	int n = p.size();
	vector<vector<int>> answer(n, vector<int>(n));
	DSU d(n+1);
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (i == j)
				continue;
			if (p[i][j]) {
				d.unite(i, j);
			}
		}
	}
	vector<vector<int>> component;
	vector<bool> done(n);
	for (int i = 0; i < n; i++) {
		if (done[i])
			continue;
		int l = d.find(i);
		vector<int> temp;
		for (int j = 0; j < n; j++) {
			if (d.find(j) == l) {
				done[j] = true;
				temp.push_back(j);
			}
		}
		if (temp.size() > 1)
			component.push_back(temp);
	}
	for (auto c : component) {
		if (sz(c) <= 1)
			continue;
		DSU dsu(n+1);
		vector<int> two;
		set<int> roots;
		for (int i = 0; i < sz(c); i++) {
			int r = c[i];
			bool o = false;
			for (int j = 0; j < n; j++) {
				if (j == r)
					continue;
				if (p[r][j] == 1) {
					o = true;
					if (dsu.same(r, j))
						continue;
					dsu.unite(r, j);
					answer[r][j] = 1;
					answer[j][r] = 1;	
					roots.insert(dsu.find(r));
				}
			}
			if (!o)
				two.push_back(r);
		}
		if (!two.empty()) {
			for (auto r : roots)
				two.push_back(r);
			for (int i = 0; i < sz(two)-1;i++) {
				answer[two[i]][two[i+1]] = 1;
				answer[two[i+1]][two[i]] = 1;
			}
			answer[two.back()][two[0]] = 1;
			answer[two[0]][two.back()] = 1;
		}
	}
	for (int i = 0; i < n; i++) {
		answer[i][i] = 0;
	}
	build(answer);
	return 1;
}

Subtask #1

11.0 / 11.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	344 KB	Output is correct
2	Correct	0 ms	348 KB	Output is correct
3	Correct	0 ms	348 KB	Output is correct
4	Correct	0 ms	344 KB	Output is correct
5	Correct	0 ms	348 KB	Output is correct
6	Correct	7 ms	1372 KB	Output is correct
7	Correct	114 ms	23988 KB	Output is correct

Subtask #2

0 / 10.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	344 KB	Output is correct
2	Correct	0 ms	348 KB	Output is correct
3	Correct	0 ms	348 KB	Output is correct
4	Correct	0 ms	344 KB	Output is correct
5	Correct	0 ms	348 KB	Output is correct
6	Correct	7 ms	1372 KB	Output is correct
7	Correct	114 ms	23988 KB	Output is correct
8	Correct	0 ms	348 KB	Output is correct
9	Correct	0 ms	348 KB	Output is correct
10	Correct	0 ms	348 KB	Output is correct
11	Correct	0 ms	344 KB	Output is correct
12	Correct	5 ms	1400 KB	Output is correct
13	Correct	110 ms	24108 KB	Output is correct
14	Incorrect	1 ms	348 KB	Answer gives possible 1 while actual possible 0
15	Halted	0 ms	0 KB	-

Subtask #3

0 / 19.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	348 KB	Output is correct
2	Correct	0 ms	348 KB	Output is correct
3	Correct	0 ms	348 KB	Output is correct
4	Incorrect	0 ms	348 KB	Answer gives possible 1 while actual possible 0
5	Halted	0 ms	0 KB	-

Subtask #4

0 / 35.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	348 KB	Output is correct
2	Correct	0 ms	348 KB	Output is correct
3	Correct	0 ms	348 KB	Output is correct
4	Correct	28 ms	6228 KB	Output is correct
5	Correct	109 ms	24148 KB	Output is correct
6	Correct	122 ms	24148 KB	Output is correct
7	Correct	114 ms	24148 KB	Output is correct
8	Correct	0 ms	344 KB	Output is correct
9	Correct	28 ms	6268 KB	Output is correct
10	Correct	113 ms	24048 KB	Output is correct
11	Correct	112 ms	24076 KB	Output is correct
12	Correct	125 ms	24196 KB	Output is correct
13	Correct	0 ms	344 KB	Output is correct
14	Correct	0 ms	348 KB	Output is correct
15	Correct	0 ms	348 KB	Output is correct
16	Incorrect	28 ms	6264 KB	Too few ways to get from 0 to 24, should be 2 found 0
17	Halted	0 ms	0 KB	-

Subtask #5

0 / 21.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	344 KB	Output is correct
2	Correct	0 ms	348 KB	Output is correct
3	Correct	0 ms	348 KB	Output is correct
4	Correct	0 ms	344 KB	Output is correct
5	Correct	0 ms	348 KB	Output is correct
6	Correct	7 ms	1372 KB	Output is correct
7	Correct	114 ms	23988 KB	Output is correct
8	Correct	0 ms	348 KB	Output is correct
9	Correct	0 ms	348 KB	Output is correct
10	Correct	0 ms	348 KB	Output is correct
11	Correct	0 ms	344 KB	Output is correct
12	Correct	5 ms	1400 KB	Output is correct
13	Correct	110 ms	24108 KB	Output is correct
14	Incorrect	1 ms	348 KB	Answer gives possible 1 while actual possible 0
15	Halted	0 ms	0 KB	-

Subtask #6

0 / 4.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	344 KB	Output is correct
2	Correct	0 ms	348 KB	Output is correct
3	Correct	0 ms	348 KB	Output is correct
4	Correct	0 ms	344 KB	Output is correct
5	Correct	0 ms	348 KB	Output is correct
6	Correct	7 ms	1372 KB	Output is correct
7	Correct	114 ms	23988 KB	Output is correct
8	Correct	0 ms	348 KB	Output is correct
9	Correct	0 ms	348 KB	Output is correct
10	Correct	0 ms	348 KB	Output is correct
11	Correct	0 ms	344 KB	Output is correct
12	Correct	5 ms	1400 KB	Output is correct
13	Correct	110 ms	24108 KB	Output is correct
14	Incorrect	1 ms	348 KB	Answer gives possible 1 while actual possible 0
15	Halted	0 ms	0 KB	-