oj.uz

Submission #1042932

# Submission time Handle Problem Language Result Execution time Memory
1042932 2024-08-03T15:00:19 Z pawned Parachute rings (IOI12_rings) C++17
55 / 100
 4000 ms 123304 KB 
#pragma GCC optimize("O1,O2,O3,Ofast,unroll-loops")

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

#define fi first
#define se second
#define pb push_back
typedef long long ll;
typedef pair<int, int> ii;
typedef vector<int> vi;

const int MAX = 1000005;

struct DSU {
	vi e;
	DSU(int N) {
		e = vi(N, -1);
	}
	int root(int x) {
		if (e[x] < 0) {
			return x;
		}
		else {
			e[x] = root(e[x]);
			return e[x];
		}
	}
	bool sameset(int x, int y) {
		return (root(x) == root(y));
	}
	bool unite(int x, int y) {
		x = root(x);
		y = root(y);
		if (x == y)
			return false;
		if (-e[x] < -e[y])
			swap(x, y);
		e[x] += e[y];
		e[y] = x;
		return true;
	}
	int size(int x) {
		return -e[root(x)];
	}
};

int N;

vi adj[MAX];

void Init(int N_) {
	N = N_;
}

void Link(int A, int B) {
	adj[A].pb(B);
	adj[B].pb(A);
}

int CountCritical() {
	vi sus;
	for (int i = 0; i < N; i++) {
		if (adj[i].size() >= 3) {
			sus.pb(i);
			if (adj[i].size() == 3) {
				for (int x : adj[i])
					sus.pb(x);
			}
			break;
		}
	}
	if ((int)(sus.size()) > 0) {
		int total = 0;
		for (int i : sus) {
			// try removing each vertex, make new adj
			// to check, ensure no adj cnt is > 2
			// and N - edge_cnt equals number of ccs
			// removed link is a chain itself
			vi adjc[N];
			int cnt = 0;
			for (int j = 0; j < N; j++) {
				if (j == i)
					continue;
				for (int k : adj[j]) {
					if (k != i) {
						adjc[j].pb(k);
						cnt++;
					}
				}
			}
			cnt /= 2;
			int maxc = 0;
			for (int j = 0; j < N; j++) {
				maxc = max(maxc, (int)(adjc[j].size()));
			}
//			cout<<"cnt, maxc: "<<cnt<<" "<<maxc<<endl;
			int ccs = 0;
			vector<bool> vis(N, false);
			for (int j = 0; j < N; j++) {
				if (!vis[j]) {
					ccs++;
					queue<int> q;
					q.push(j);
					vis[j] = true;
					while (!q.empty()) {
						int x = q.front();
						q.pop();
						for (int y : adjc[x]) {
							if (!vis[y]) {
								q.push(y);
								vis[y] = true;
							}
						}
					}
				}
			}
//			cout<<"ccs: "<<ccs<<endl;
			if ((maxc <= 2) && (N - cnt == ccs))
				total++;
		}
		return total;
	}
	else {	// all vertices have degree <= 2
		// all lines or cycles
		int cnt = 0;
		for (int j = 0; j < N; j++) {
			cnt += (int)(adj[j].size());
		}
		cnt /= 2;
		int ccs = 0;
		vector<bool> vis(N, false);
		for (int j = 0; j < N; j++) {
			if (!vis[j]) {
				ccs++;
				queue<int> q;
				q.push(j);
				vis[j] = true;
				while (!q.empty()) {
					int x = q.front();
					q.pop();
					for (int y : adj[x]) {
						if (!vis[y]) {
							q.push(y);
							vis[y] = true;
						}
					}
				}
			}
		}
		if (N - cnt == ccs) {
			return N;
		}
		else if (N - cnt == ccs - 1) {	// one cycle, find length
			// given adjacency list, find the cycle
			// find all components, then find # edges in comp
			DSU dsu(N);
			for (int i = 0; i < N; i++) {
				for (int j : adj[i])
					dsu.unite(i, j);
			}
			vector<vi> incomp(N);	// N vectors
			for (int i = 0; i < N; i++) {
				incomp[dsu.root(i)].pb(i);
			}
			int ans = -1;
			for (int i = 0; i < N; i++) {
				if ((int)(incomp[i].size()) != 0) {
					int sumd = 0;
					for (int j : incomp[i])
						sumd += (int)(adj[j].size());
					if (sumd / 2 == (int)(incomp[i].size())) {
						ans = sumd / 2;
						break;
					}
				}
			}
			return ans;
		}
		else {
			return 0;
		}
	}
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23900 KB Output is correct
2 Correct 13 ms 24352 KB Output is correct
3 Correct 13 ms 24412 KB Output is correct
4 Correct 12 ms 24008 KB Output is correct
5 Correct 11 ms 24156 KB Output is correct
6 Correct 12 ms 24156 KB Output is correct
7 Correct 12 ms 23984 KB Output is correct
8 Correct 12 ms 23900 KB Output is correct
9 Correct 15 ms 24184 KB Output is correct
10 Correct 13 ms 24412 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 189 ms 46932 KB Output is correct
2 Correct 559 ms 103248 KB Output is correct
3 Correct 1072 ms 115148 KB Output is correct
4 Correct 705 ms 101712 KB Output is correct
5 Correct 701 ms 101456 KB Output is correct
6 Correct 665 ms 99524 KB Output is correct
7 Correct 584 ms 113488 KB Output is correct
8 Correct 1682 ms 116872 KB Output is correct
9 Correct 1823 ms 123304 KB Output is correct
10 Correct 459 ms 66208 KB Output is correct

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23900 KB Output is correct
2 Correct 13 ms 24352 KB Output is correct
3 Correct 13 ms 24412 KB Output is correct
4 Correct 12 ms 24008 KB Output is correct
5 Correct 11 ms 24156 KB Output is correct
6 Correct 12 ms 24156 KB Output is correct
7 Correct 12 ms 23984 KB Output is correct
8 Correct 12 ms 23900 KB Output is correct
9 Correct 15 ms 24184 KB Output is correct
10 Correct 13 ms 24412 KB Output is correct
11 Correct 64 ms 24400 KB Output is correct
12 Correct 52 ms 24936 KB Output is correct
13 Correct 151 ms 24652 KB Output is correct
14 Correct 145 ms 24544 KB Output is correct
15 Correct 248 ms 24616 KB Output is correct
16 Correct 39 ms 24556 KB Output is correct
17 Correct 200 ms 24660 KB Output is correct
18 Correct 341 ms 25200 KB Output is correct
19 Correct 37 ms 24656 KB Output is correct
20 Correct 120 ms 24868 KB Output is correct

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23900 KB Output is correct
2 Correct 13 ms 24352 KB Output is correct
3 Correct 13 ms 24412 KB Output is correct
4 Correct 12 ms 24008 KB Output is correct
5 Correct 11 ms 24156 KB Output is correct
6 Correct 12 ms 24156 KB Output is correct
7 Correct 12 ms 23984 KB Output is correct
8 Correct 12 ms 23900 KB Output is correct
9 Correct 15 ms 24184 KB Output is correct
10 Correct 13 ms 24412 KB Output is correct
11 Correct 64 ms 24400 KB Output is correct
12 Correct 52 ms 24936 KB Output is correct
13 Correct 151 ms 24652 KB Output is correct
14 Correct 145 ms 24544 KB Output is correct
15 Correct 248 ms 24616 KB Output is correct
16 Correct 39 ms 24556 KB Output is correct
17 Correct 200 ms 24660 KB Output is correct
18 Correct 341 ms 25200 KB Output is correct
19 Correct 37 ms 24656 KB Output is correct
20 Correct 120 ms 24868 KB Output is correct
21 Execution timed out 4040 ms 24100 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23900 KB Output is correct
2 Correct 13 ms 24352 KB Output is correct
3 Correct 13 ms 24412 KB Output is correct
4 Correct 12 ms 24008 KB Output is correct
5 Correct 11 ms 24156 KB Output is correct
6 Correct 12 ms 24156 KB Output is correct
7 Correct 12 ms 23984 KB Output is correct
8 Correct 12 ms 23900 KB Output is correct
9 Correct 15 ms 24184 KB Output is correct
10 Correct 13 ms 24412 KB Output is correct
11 Correct 189 ms 46932 KB Output is correct
12 Correct 559 ms 103248 KB Output is correct
13 Correct 1072 ms 115148 KB Output is correct
14 Correct 705 ms 101712 KB Output is correct
15 Correct 701 ms 101456 KB Output is correct
16 Correct 665 ms 99524 KB Output is correct
17 Correct 584 ms 113488 KB Output is correct
18 Correct 1682 ms 116872 KB Output is correct
19 Correct 1823 ms 123304 KB Output is correct
20 Correct 459 ms 66208 KB Output is correct
21 Correct 64 ms 24400 KB Output is correct
22 Correct 52 ms 24936 KB Output is correct
23 Correct 151 ms 24652 KB Output is correct
24 Correct 145 ms 24544 KB Output is correct
25 Correct 248 ms 24616 KB Output is correct
26 Correct 39 ms 24556 KB Output is correct
27 Correct 200 ms 24660 KB Output is correct
28 Correct 341 ms 25200 KB Output is correct
29 Correct 37 ms 24656 KB Output is correct
30 Correct 120 ms 24868 KB Output is correct
31 Execution timed out 4040 ms 24100 KB Time limit exceeded
32 Halted 0 ms 0 KB -