oj.uz

Submission #1087815

# Submission time Handle Problem Language Result Execution time Memory
1087815 2024-09-13T09:12:32 Z mychecksedad Sprinklers (CEOI24_sprinklers) C++17
6 / 100
 468 ms 6484 KB 
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define pb push_back
#define en cout << '\n'
#define vi vector<int>
#define pii pair<int, int>
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
const int N = 1e5+100;


int n, m, a[N], b[N];
int dp[N][2], par[N][2];
int get(int l, int r){
	if(r < l) return 0;
	return upper_bound(b+1, b+1+m, r) - lower_bound(b+1, b+1+m, l);
}
int get_first(int l){
	int pos =	lower_bound(b+1, b+1+m, l) - b;
	if(pos == m+1) return 2e9;
	return b[pos]; 
}
void solve(){
	cin >> n >> m;
	vector<pii> v;
	for(int i = 1; i <= n; ++i){
		cin >> a[i];
		v.pb({a[i], 1});
	}
	for(int i = 1; i <= m; ++i){
		cin >> b[i];
		v.pb({b[i], 0});
	}
	sort(all(v));
	string soll;
	int l = 0, r = 1e9+2, ans = -1;
	while(l <= r){
		int k = l+r>>1;
		string sol = "";
		bool ok = 1;
		int last_covered = -2e9;
		dp[1][0] = get(-2e9, a[1] - k - 1) > 0 ? (int)(-2e9) : get_first(a[1] + 1);
		dp[1][1] = get(-2e9, a[1]) > 0 ? (int)(-2e9) : get_first(a[1] + k + 1);
		for(int i = 2; i <= n ;++i){
			int L = a[i] - k, R = a[i];
			if(dp[i - 1][0] >= L){
				dp[i][0] = get_first(a[i] + 1);
				par[i][0] = 0;
			}else{
				dp[i][0] = -2e9;
			}

			if(dp[i - 1][0] >= a[i]){
				par[i][1] = 0;
				dp[i][1] = get_first(a[i] + k + 1);
			}else{
				dp[i][1] = -2e9;
			}

			if(dp[i-1][1] >= L){
				if(dp[i][0] < get_first(a[i] + 1)){
					par[i][0] = 1;
				}
				dp[i][0] = max(dp[i][0], get_first(a[i] + 1));
			}else{
				dp[i][0] = max(dp[i][0], (int)(-2e9));
			}

			if(dp[i-1][1] >= a[i]){
				if(dp[i][1] < get_first(a[i] + k + 1)){
					par[i][1] = 1;
				}
				dp[i][1] = max(dp[i][1], get_first(a[i] + k + 1));
			}else{
				dp[i][1] = max(dp[i][1], (int)(-2e9));
			}
		}
		if(max(dp[n][0], dp[n][1]) == (int)2e9){
			ok = 1;
			int x = 0;
			if(dp[n][0] == 2e9) x = 0;
			else x = 1;
			sol += (x==0?'L':'R');
			for(int i = n - 1; i >= 1; --i){
				x = par[i + 1][x];
				sol += (x==0?'L':'R');
			}
			reverse(all(sol));	
		}
		else ok = 0;
		


		if(ok){
			ans = k;
			soll = sol;
			r = k - 1;
		}else{
			l = k + 1;
		}
	}

	cout << ans << '\n';
	if(ans != -1){
		cout << soll;
	}
}

int main(){
	cin.tie(0); ios::sync_with_stdio(0);
	solve();
	return 0;
}

Compilation message

Main.cpp: In function 'void solve()':
Main.cpp:40:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   40 |   int k = l+r>>1;
      |           ~^~
Main.cpp:47:22: warning: unused variable 'R' [-Wunused-variable]
   47 |    int L = a[i] - k, R = a[i];
      |                      ^
Main.cpp:43:7: warning: unused variable 'last_covered' [-Wunused-variable]
   43 |   int last_covered = -2e9;
      |       ^~~~~~~~~~~~

Subtask #0
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 2396 KB Correct
2 Correct 0 ms 2396 KB Correct

Subtask #1
0.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 2396 KB Correct
2 Correct 9 ms 4316 KB Correct
3 Incorrect 1 ms 2392 KB User solution is worse than jury's solution
4 Halted 0 ms 0 KB -

Subtask #2
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 2396 KB Correct
2 Correct 19 ms 4572 KB Correct
3 Correct 34 ms 2908 KB Correct
4 Correct 400 ms 6384 KB Correct
5 Correct 454 ms 6384 KB Correct
6 Correct 0 ms 2396 KB Correct
7 Correct 1 ms 2396 KB Correct
8 Correct 216 ms 6484 KB Correct
9 Correct 216 ms 6396 KB Correct
10 Correct 398 ms 6348 KB Correct
11 Correct 169 ms 4876 KB Correct
12 Correct 184 ms 5072 KB Correct
13 Correct 407 ms 5632 KB Correct
14 Correct 377 ms 5984 KB Correct
15 Correct 402 ms 6104 KB Correct
16 Correct 387 ms 5592 KB Correct

Subtask #3
0.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 2396 KB Correct
2 Correct 0 ms 2396 KB Correct
3 Correct 1 ms 2392 KB Correct
4 Correct 1 ms 2396 KB Correct
5 Incorrect 1 ms 2396 KB User solution is worse than jury's solution
6 Halted 0 ms 0 KB -

Subtask #4
0.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 2396 KB Correct
2 Correct 65 ms 4568 KB Correct
3 Incorrect 468 ms 6348 KB User solution is worse than jury's solution
4 Halted 0 ms 0 KB -

Subtask #5
0.0 / 47.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 2396 KB Correct
2 Correct 0 ms 2396 KB Correct
3 Correct 9 ms 4316 KB Correct
4 Incorrect 1 ms 2392 KB User solution is worse than jury's solution
5 Halted 0 ms 0 KB -