oj.uz

Submission #562475

# Submission time Handle Problem Language Result Execution time Memory
562475 2022-05-14T12:44:37 Z aryan12 Lamps (JOI19_lamps) C++17
4 / 100
 191 ms 35592 KB 
#include <bits/stdc++.h>
using namespace std;
#define int long long

mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());

int n;
string a, b;

const int N = 1e6 + 5;
int seg[N * 4];

void Build(int l, int r, int pos)
{
	if(l == r)
	{
		seg[pos] = a[l] - '0';
		return;
	}
	int mid = (l + r) >> 1;
	Build(l, mid, pos * 2);
	Build(mid + 1, r, pos * 2 + 1);
	seg[pos] = seg[pos * 2] + seg[pos * 2 + 1];
}

int Query(int l, int r, int pos, int ql, int qr)
{
	if(ql <= l && r <= qr)
	{
		return seg[pos];
	}
	if(ql > r || l > qr)
	{
		return 0;
	}
	int mid = (l + r) >> 1;
	return Query(l, mid, pos * 2, ql, qr) + Query(mid + 1, r, pos * 2 + 1, ql, qr);
}

void Solve() 
{
	cin >> n >> a >> b;
	Build(0, n - 1, 1);
	int prev_value = b[0] - '0', start_pos = 0;
	vector<array<int, 2> > values; // {update, toggle}
	for(int i = 1; i < n; i++)
	{
		if(prev_value != b[i] - '0')
		{
			int ans = Query(0, n - 1, 1, start_pos, i - 1);
			int len = i - 1 - start_pos + 1;
			if((ans == len && prev_value == 1) || (ans == 0 && prev_value == 0)) // no need to "update"
			{
				values.push_back({0, 1}); //0 for set state, 1 (+ 1) for toggle state
			}
			else if((ans == len && prev_value == 0) || (ans == 0 && prev_value == 1)) // no need to toggle
			{
				values.push_back({1, 0});
			}
			else
			{
				values.push_back({1, 1});
			}
			start_pos = i;
			prev_value = b[i] - '0';
		}
	}
	int ans = Query(0, n - 1, 1, start_pos, n - 1);
	int len = n - 1 - start_pos + 1;
	if((ans == len && prev_value == 1) || (ans == 0 && prev_value == 0))
	{
		values.push_back({0, 1});
	}
	else if((ans == len && prev_value == 0) || (ans == 0 && prev_value == 1))
	{
		values.push_back({1, 0});
	}
	else
	{
		values.push_back({1, 1});
	}
	// for(int i = 0; i < values.size(); i++)
	// {
	// 	cout << values[i][0] << " " << values[i][1] << "\n";
	// }
	bool istoggleon = false;
	ans = 0;
	int cnt = 0;
	for(int i = 0; i < values.size(); i++)
	{
		if(values[i][0] == 0 && values[i][1] == 1)
		{
			istoggleon = false;
			// ans += values[i][0] = 0
		}
		else if(values[i][0] == 1 && values[i][1] == 0)
		{
			if(!istoggleon) ans++; // for opening toggle
			istoggleon = true;
			if(cnt >= 3) // better to toggle
			{
				ans -= cnt;
				ans += cnt / 2 + 1;
			}
			cnt = 0;
		}
		else
		{
			ans++;
			// if(istoggleon) ans += values[i][1];
			// else 		  ans += values[i][0];
		}
		if(!istoggleon)
		{
			cnt++;
		}
	}
	ans = min(ans, ans - cnt + cnt / 2 + 2); // if we toggle the last steps
	cout << ans << "\n";
}

int32_t main() 
{
	auto begin = std::chrono::high_resolution_clock::now();
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int t = 1;
	// cin >> t;
	for(int i = 1; i <= t; i++) 
	{
		//cout << "Case #" << i << ": ";
		Solve();
	}
	auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n"; 
	return 0;
}

Compilation message

lamp.cpp: In function 'void Solve()':
lamp.cpp:89:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   89 |  for(int i = 0; i < values.size(); i++)
      |                 ~~^~~~~~~~~~~~~~~

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Incorrect 0 ms 212 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #2
0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Incorrect 0 ms 212 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #3
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 21 ms 18736 KB Output is correct
8 Correct 173 ms 35588 KB Output is correct
9 Correct 154 ms 35592 KB Output is correct
10 Correct 191 ms 35560 KB Output is correct
11 Correct 171 ms 35528 KB Output is correct
12 Correct 19 ms 18856 KB Output is correct
13 Correct 21 ms 18852 KB Output is correct
14 Correct 27 ms 19528 KB Output is correct

Subtask #4
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Incorrect 0 ms 212 KB Output isn't correct
13 Halted 0 ms 0 KB -