oj.uz

Submission #1044207

# Submission time Handle Problem Language Result Execution time Memory
1044207 2024-08-05T08:01:37 Z 김은성(#11005) Parking (CEOI22_parking) C++17
50 / 100
 142 ms 29920 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());
		stack<int> qa;
		for(int c: cols){
			if(color[c].size() >= 2)
				qa.push(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)
					qa.push(c);
			}
		}
		//printf("qa.size=%d\n", qa.size());
		while(!qa.empty()){
			//printf("qa.front=%d\n", qa.front());
			if(done[qa.top()]){
				qa.pop();
				continue;
			}
			int from = color[qa.top()][0], to = color[qa.top()][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.top()] = 1;
			qa.pop();
			for(int c: {b[from], b[to]}){
				if(c && color[c].size() == 2){
					qa.push(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:91:28: warning: comparison of integer expressions of different signedness: 'std::stack<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   91 |   if(m-n == 1 && qa.size() > m-n){
      |                  ~~~~~~~~~~^~~~~
Main.cpp:138:11: 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=]
  138 |  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 11356 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 83 ms 27072 KB Output is correct
2 Correct 95 ms 29920 KB Output is correct
3 Correct 69 ms 28440 KB Output is correct
4 Correct 68 ms 28300 KB Output is correct
5 Correct 128 ms 29888 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 11356 KB Output is correct
2 Correct 3 ms 11352 KB Output is correct
3 Correct 2 ms 11356 KB Output is correct
4 Correct 3 ms 11356 KB Output is correct
5 Correct 2 ms 11356 KB Output is correct
6 Correct 2 ms 11356 KB Output is correct
7 Correct 3 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 3 ms 11356 KB Output is correct
2 Correct 3 ms 11352 KB Output is correct
3 Correct 2 ms 11356 KB Output is correct
4 Correct 3 ms 11356 KB Output is correct
5 Correct 2 ms 11356 KB Output is correct
6 Correct 2 ms 11356 KB Output is correct
7 Correct 3 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 138 ms 28972 KB Output is correct
11 Correct 48 ms 23376 KB Output is correct
12 Correct 56 ms 23428 KB Output is correct
13 Correct 130 ms 28108 KB Output is correct
14 Correct 63 ms 22156 KB Output is correct
15 Correct 57 ms 22056 KB Output is correct
16 Correct 142 ms 29208 KB Output is correct
17 Correct 51 ms 22652 KB Output is correct
18 Correct 127 ms 28860 KB Output is correct

Subtask #5
0.0 / 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 Incorrect 3 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 11356 KB Output isn't correct
3 Halted 0 ms 0 KB -