oj.uz

Submission #1044253

# Submission time Handle Problem Language Result Execution time Memory
1044253 2024-08-05T08:23:19 Z 김은성(#11005) Parking (CEOI22_parking) C++17
50 / 100
 135 ms 42692 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);
	//assert(m<=4);
	for(i=1; i<=m; i++){
		scanf("%d %d", &b[i], &t[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;
	}
	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);
					}
				}
			}
		}
	}
	for(i=1; i<=m; i++){
		if(!b[i] || !t[i])
			continue;
		graph[b[i]].push_back(make_pair(i, t[i]));
		graph[t[i]].push_back(make_pair(i, b[i]));
	}
	for(i=1; i<=n; i++){
		assert(graph[i].size());
		if(done[i] || 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);
			}
		}
		//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:183:11: 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=]
  183 |  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:59:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 |   scanf("%d %d", &b[i], &t[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# 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 2 ms 11356 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 11352 KB Output is correct
10 Correct 3 ms 11356 KB Output is correct

Subtask #2
0.0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 55 ms 42692 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

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 11352 KB Output is correct
3 Correct 2 ms 11356 KB Output is correct
4 Correct 2 ms 11352 KB Output is correct
5 Correct 2 ms 11352 KB Output is correct
6 Correct 2 ms 11356 KB Output is correct
7 Correct 2 ms 11352 KB Output is correct
8 Correct 3 ms 11356 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 11352 KB Output is correct
3 Correct 2 ms 11356 KB Output is correct
4 Correct 2 ms 11352 KB Output is correct
5 Correct 2 ms 11352 KB Output is correct
6 Correct 2 ms 11356 KB Output is correct
7 Correct 2 ms 11352 KB Output is correct
8 Correct 3 ms 11356 KB Output is correct
9 Correct 2 ms 11356 KB Output is correct
10 Correct 116 ms 29096 KB Output is correct
11 Correct 32 ms 17400 KB Output is correct
12 Correct 39 ms 17236 KB Output is correct
13 Correct 120 ms 28168 KB Output is correct
14 Correct 33 ms 15952 KB Output is correct
15 Correct 51 ms 21948 KB Output is correct
16 Correct 135 ms 29432 KB Output is correct
17 Correct 51 ms 22612 KB Output is correct
18 Correct 118 ms 28860 KB Output is correct

Subtask #5
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Runtime error 9 ms 22872 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #6
0.0 / 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 2 ms 11356 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 11352 KB Output is correct
10 Correct 3 ms 11356 KB Output is correct
11 Runtime error 55 ms 42692 KB Execution killed with signal 6
12 Halted 0 ms 0 KB -