oj.uz

Submission #642314

# Submission time Handle Problem Language Result Execution time Memory
642314 2022-09-19T08:27:45 Z dozer Joker (BOI20_joker) C++14
0 / 100
 3 ms 468 KB 
#include <bits/stdc++.h>
using namespace std;
#define fileio() freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#define fastio() cin.tie(0), ios_base::sync_with_stdio(0)
#define sp " "
#define endl "\n"
#define pb push_back
#define pii pair<int, int>
#define st first
#define nd second
#define N 200005
 
const int modulo = 1e9 + 7;
int ans[N], u[N], v[N], l[N], r[N];
 
int find(vector<int> &root, int node)
{
	if (node < 0) return -(find(root, -node));
	if (node == root[node]) return node;
	return root[node] = find(root, root[node]);
}
 
 
int32_t main()
{
	fileio();
	fastio();
 

	int n, m, q;
	cin>>n>>m>>q;
	vector<int> root(n + 5, 0);
	for (int i = 1; i <= n; i++)
		root[i] = i;
 
	for (int i = 1; i <= m; i++)
	{
		cin>>u[i]>>v[i];
	}
 
	for (int i = m; i >= 1; i--)
	{
		if (ans[i] == 1) 
		{
			ans[i - 1] = 1;
			continue;
		}
		int a = find(root, u[i]), b = find(root, v[i]);
		if (a == b) ans[i - 1] = 1;
		else
		{
			if (a < 0) a *= -1, b *= -1;
			root[a] = -b;
		}
	}
 
	for (int i = 1; i <= q; i++)
	{
		cin>>l[i]>>r[i];
		if (ans[r[i]] == 1) cout<<"YES\n";
		else cout<<"NO\n";
	}
	cerr<<"time taken : "<<(float)clock() / CLOCKS_PER_SEC<<" seconds\n";
}

Compilation message

Joker.cpp: In function 'int32_t main()':
Joker.cpp:3:25: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fileio() freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
      |                  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Joker.cpp:26:2: note: in expansion of macro 'fileio'
   26 |  fileio();
      |  ^~~~~~
Joker.cpp:3:59: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fileio() freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
      |                                                    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
Joker.cpp:26:2: note: in expansion of macro 'fileio'
   26 |  fileio();
      |  ^~~~~~

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 468 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 8.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 468 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 25.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 468 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 468 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 468 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 29.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 468 KB Output isn't correct
2 Halted 0 ms 0 KB -