oj.uz

Submission #1044229

# Submission time Handle Problem Language Result Execution time Memory
1044229 2024-08-05T08:11:13 Z 김은성(#11005) Parking (CEOI22_parking) C++17
50 / 100
 186 ms 31944 KB 
#include <bits/stdc++.h>
using namespace std;
bool ch[200009];
vector<pair<int, int> > graph[200009];
int b[200009], t[200009];
unordered_set<int> emp;
vector<int> color[200009];
vector<pair<int, int> > ans;
vector<int> comp, cols;
bool done[200009];
void dfs(int v){
	ch[v] = 1;
	cols.push_back(v);
	for(auto [e, u]: graph[v]){
		comp.push_back(e);
		if(!ch[u]){
			dfs(u);
		}
	}
}
void makemove(int occ, int e){
	//printf("from=%d to=%d\n", occ, e);
	ans.push_back(make_pair(occ, e));
	if(t[occ]){
		color[t[occ]].erase(find(color[t[occ]].begin(), color[t[occ]].end(), occ));
		color[b[occ]].push_back(occ);
		if(b[e]){
			t[e] = t[occ];
			t[occ] = 0;
		}
		else{
			b[e] = t[occ];
			t[occ] = 0;
			emp.erase(e);
			color[b[e]].push_back(e);
		}
	}
	else{
		color[b[occ]].erase(find(color[b[occ]].begin(), color[b[occ]].end(), occ));
		emp.insert(occ);
		if(b[e]){
			t[e] = b[occ];
			b[occ] = 0;
		}
		else{
			b[e] = b[occ];
			t[occ] = 0;
			emp.erase(e);
			color[b[e]].push_back(e);
		}
	}
}
int main(){
	int n, m, i, j, ans2 = 0;
	bool flag = 0;
	scanf("%d %d", &n, &m);
	for(i=1; i<=m; i++){
		scanf("%d %d", &b[i], &t[i]);
		graph[b[i]].push_back(make_pair(i, t[i]));
		graph[t[i]].push_back(make_pair(i, b[i]));
		if(b[i] != t[i])
			flag = 1, ans2++;
		if(b[i] + t[i] == 0)
			emp.insert(i);
		if(t[i])
			color[t[i]].push_back(i);
		else if(b[i])
			color[b[i]].push_back(i);
	}
	queue<int> q;
	for(int c=1; c<=n; c++){
		if(color[c].size() >= 2){
			if(!t[color[c][0]] || !t[color[c][1]]){
				q.push(c);
			}
		}
	}
	while(!q.empty()){
		int c = q.front();
		q.pop();
		if(color[c].size() >= 2){
			if(!t[color[c][0]] || !t[color[c][1]]){
				if(!t[color[c][0]]){
					makemove(color[c][1], color[c][0]);
					done[c] = 1;
					int temp = b[color[c][1]];
					if(temp && !done[temp] && color[temp].size() >= 2){
						q.push(temp);
					}
				}
				else{
					makemove(color[c][0], color[c][1]);
					done[c] = 1;
					int temp = b[color[c][0]];
					if(temp && !done[temp] && color[temp].size() >= 2){
						q.push(temp);
					}
				}
			}
		}
	}
	if(n==m){
		if(flag)
			printf("-1\n");
		else
			printf("0\n");
		return 0;
	}
	for(i=1; i<=n; i++){
		if(ch[i] || graph[i][0].second == i)
			continue;
		comp.clear();
		cols.clear();
		//printf("i=%d\n", i);
		dfs(i);
		sort(comp.begin(), comp.end());
		comp.erase(unique(comp.begin(), comp.end()), comp.end());
		deque<int> qa;
		for(int c: cols){
			if(color[c].size() >= 2){
				if(!t[color[c][0]] || !t[color[c][1]])
					qa.push_front(c);
				else
					qa.push_back(c);
			}
		}
		if(m-n == 1 && qa.size() > m-n){
			printf("-1\n");
			return 0;
		}
		//printf("emp.size=%d\n", emp.size());
		if(qa.empty()){
			int occ = comp[0], e = *emp.begin();
			//printf("occ=%d e=%d\n", occ, e);
			makemove(occ, e);
			for(int c: cols){
				if(color[c].size() >= 2){
					if(!t[color[c][0]] || !t[color[c][1]])
						qa.push_front(c);
					else
						qa.push_back(c);
				}
			}
		}
		//printf("qa.size=%d\n", qa.size());
		while(!qa.empty()){
			//printf("qa.front=%d\n", qa.front());
			if(done[qa.front()]){
				qa.pop_front();
				continue;
			}
			int from = color[qa.front()][0], to = color[qa.front()][1];
			//printf("from=%d to=%d\n", from, to);
			if(t[to])
				swap(from, to);
			if(t[to]){
				if(emp.empty()){
					printf("-1\n");
					return 0;
				}
				int e = *emp.begin();
				//printf("from=%d to=%d e=%d\n", from, to, e);
				makemove(from, e);
				makemove(to, e);
			}
			else{
				makemove(from, to);
			}
			done[qa.front()] = 1;
			qa.pop_front();
			for(int c: {b[from], b[to]}){
				if(c && color[c].size() == 2){
					if(!t[color[c][0]] || !t[color[c][1]])
						qa.push_front(c);
					else
						qa.push_back(c);
				}
			}
		}
	}
	printf("%d\n", ans.size());
	for(auto [u, v]: ans){
		printf("%d %d\n", u, v);
	}
	return 0;
}

Compilation message

Main.cpp: In function 'int main()':
Main.cpp:127:28: warning: comparison of integer expressions of different signedness: 'std::deque<int, std::allocator<int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  127 |   if(m-n == 1 && qa.size() > m-n){
      |                  ~~~~~~~~~~^~~~~
Main.cpp:181:11: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wformat=]
  181 |  printf("%d\n", ans.size());
      |          ~^     ~~~~~~~~~~
      |           |             |
      |           int           std::vector<std::pair<int, int> >::size_type {aka long unsigned int}
      |          %ld
Main.cpp:54:15: warning: unused variable 'j' [-Wunused-variable]
   54 |  int n, m, i, j, ans2 = 0;
      |               ^
Main.cpp:56:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |  scanf("%d %d", &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~~
Main.cpp:58:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   58 |   scanf("%d %d", &b[i], &t[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 11364 KB Output is correct
2 Incorrect 2 ms 11364 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 133 ms 28044 KB Output is correct
2 Correct 127 ms 28872 KB Output is correct
3 Correct 89 ms 27828 KB Output is correct
4 Correct 114 ms 29016 KB Output is correct
5 Correct 135 ms 28788 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 11356 KB Output is correct
2 Correct 3 ms 11352 KB Output is correct
3 Correct 3 ms 11352 KB Output is correct
4 Correct 2 ms 11356 KB Output is correct
5 Correct 3 ms 11356 KB Output is correct
6 Correct 3 ms 11356 KB Output is correct
7 Correct 4 ms 11356 KB Output is correct
8 Correct 3 ms 11356 KB Output is correct
9 Correct 3 ms 11356 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 11356 KB Output is correct
2 Correct 3 ms 11352 KB Output is correct
3 Correct 3 ms 11352 KB Output is correct
4 Correct 2 ms 11356 KB Output is correct
5 Correct 3 ms 11356 KB Output is correct
6 Correct 3 ms 11356 KB Output is correct
7 Correct 4 ms 11356 KB Output is correct
8 Correct 3 ms 11356 KB Output is correct
9 Correct 3 ms 11356 KB Output is correct
10 Correct 168 ms 31476 KB Output is correct
11 Correct 87 ms 25940 KB Output is correct
12 Correct 90 ms 25952 KB Output is correct
13 Correct 176 ms 30672 KB Output is correct
14 Correct 96 ms 24664 KB Output is correct
15 Correct 79 ms 24372 KB Output is correct
16 Correct 181 ms 31944 KB Output is correct
17 Correct 96 ms 25172 KB Output is correct
18 Correct 186 ms 31180 KB Output is correct

Subtask #5
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 11356 KB Output is correct
2 Correct 3 ms 11356 KB Output is correct
3 Correct 3 ms 11356 KB Output is correct
4 Correct 2 ms 11356 KB Output is correct
5 Correct 2 ms 11352 KB Output is correct
6 Correct 4 ms 11356 KB Output is correct
7 Correct 2 ms 11352 KB Output is correct
8 Incorrect 3 ms 11352 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #6
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 11364 KB Output is correct
2 Incorrect 2 ms 11364 KB Output isn't correct
3 Halted 0 ms 0 KB -