oj.uz

Submission #1044214

# Submission time Handle Problem Language Result Execution time Memory
1044214 2024-08-05T08:04:02 Z 김은성(#11005) Parking (CEOI22_parking) C++17
50 / 100
 138 ms 29324 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);
	}
	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:95:28: warning: comparison of integer expressions of different signedness: 'std::deque<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   95 |   if(m-n == 1 && qa.size() > m-n){
      |                  ~~~~~~~~~~^~~~~
Main.cpp:149:11: 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=]
  149 |  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 11352 KB Output is correct
2 Incorrect 2 ms 11352 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 75 ms 27388 KB Output is correct
2 Correct 105 ms 28608 KB Output is correct
3 Correct 68 ms 25908 KB Output is correct
4 Correct 66 ms 27948 KB Output is correct
5 Correct 96 ms 28348 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 2 ms 11356 KB Output is correct
3 Correct 2 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 3 ms 11352 KB Output is correct
7 Correct 2 ms 11352 KB Output is correct
8 Correct 2 ms 11352 KB Output is correct
9 Correct 2 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 2 ms 11356 KB Output is correct
3 Correct 2 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 3 ms 11352 KB Output is correct
7 Correct 2 ms 11352 KB Output is correct
8 Correct 2 ms 11352 KB Output is correct
9 Correct 2 ms 11356 KB Output is correct
10 Correct 134 ms 28964 KB Output is correct
11 Correct 52 ms 23564 KB Output is correct
12 Correct 63 ms 23380 KB Output is correct
13 Correct 105 ms 28108 KB Output is correct
14 Correct 80 ms 22096 KB Output is correct
15 Correct 80 ms 22096 KB Output is correct
16 Correct 138 ms 29324 KB Output is correct
17 Correct 68 ms 22608 KB Output is correct
18 Correct 127 ms 28836 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 Incorrect 2 ms 11352 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #6
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 11352 KB Output is correct
2 Incorrect 2 ms 11352 KB Output isn't correct
3 Halted 0 ms 0 KB -