oj.uz

Submission #1044261

# Submission time Handle Problem Language Result Execution time Memory
1044261 2024-08-05T08:25:56 Z 김은성(#11005) Parking (CEOI22_parking) C++17
50 / 100
 138 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];
			b[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 11352 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 11352 KB Output is correct
5 Correct 2 ms 11352 KB Output is correct
6 Correct 2 ms 11352 KB Output is correct
7 Correct 2 ms 11356 KB Output is correct
8 Correct 2 ms 11352 KB Output is correct
9 Correct 2 ms 11356 KB Output is correct
10 Correct 2 ms 11356 KB Output is correct

Subtask #2
0.0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 53 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 11356 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 11352 KB Output is correct
7 Correct 4 ms 11356 KB Output is correct
8 Correct 2 ms 11356 KB Output is correct
9 Correct 2 ms 11352 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 11352 KB Output is correct
5 Correct 2 ms 11352 KB Output is correct
6 Correct 2 ms 11352 KB Output is correct
7 Correct 4 ms 11356 KB Output is correct
8 Correct 2 ms 11356 KB Output is correct
9 Correct 2 ms 11352 KB Output is correct
10 Correct 112 ms 29100 KB Output is correct
11 Correct 33 ms 17444 KB Output is correct
12 Correct 31 ms 17232 KB Output is correct
13 Correct 125 ms 28108 KB Output is correct
14 Correct 32 ms 15952 KB Output is correct
15 Correct 49 ms 22092 KB Output is correct
16 Correct 127 ms 29224 KB Output is correct
17 Correct 48 ms 22612 KB Output is correct
18 Correct 138 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 11352 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 11352 KB Output is correct
5 Correct 2 ms 11352 KB Output is correct
6 Correct 2 ms 11352 KB Output is correct
7 Correct 2 ms 11356 KB Output is correct
8 Correct 2 ms 11352 KB Output is correct
9 Correct 2 ms 11356 KB Output is correct
10 Correct 2 ms 11356 KB Output is correct
11 Runtime error 53 ms 42692 KB Execution killed with signal 6
12 Halted 0 ms 0 KB -