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Submission #1087851

# Submission time Handle Problem Language Result Execution time Memory
1087851 2024-09-13T10:18:28 Z mychecksedad Sprinklers (CEOI24_sprinklers) C++17
9 / 100
 477 ms 6624 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] - 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] = dp[i - 1][0];
				par[i][1] = 0;
			}

			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], dp[i - 1][1]);
			}
		}
		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 1 ms 344 KB Correct
2 Correct 0 ms 348 KB Correct

Subtask #1
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Correct
2 Correct 7 ms 2524 KB Correct
3 Correct 0 ms 348 KB Correct
4 Correct 9 ms 2780 KB Correct
5 Correct 9 ms 2776 KB Correct
6 Correct 1 ms 344 KB Correct
7 Correct 0 ms 348 KB Correct
8 Correct 2 ms 1116 KB Correct
9 Correct 0 ms 348 KB Correct

Subtask #2
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Correct
2 Correct 22 ms 2776 KB Correct
3 Correct 35 ms 860 KB Correct
4 Correct 412 ms 6596 KB Correct
5 Correct 455 ms 6532 KB Correct
6 Correct 1 ms 344 KB Correct
7 Correct 0 ms 348 KB Correct
8 Correct 214 ms 6556 KB Correct
9 Correct 217 ms 6600 KB Correct
10 Correct 399 ms 6600 KB Correct
11 Correct 163 ms 4560 KB Correct
12 Correct 183 ms 3936 KB Correct
13 Correct 414 ms 5372 KB Correct
14 Correct 368 ms 5572 KB Correct
15 Correct 415 ms 5580 KB Correct
16 Correct 386 ms 5292 KB Correct

Subtask #3
0.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Correct
2 Correct 0 ms 348 KB Correct
3 Correct 1 ms 348 KB Correct
4 Correct 0 ms 348 KB Correct
5 Incorrect 1 ms 348 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 1 ms 344 KB Correct
2 Correct 62 ms 3112 KB Correct
3 Incorrect 477 ms 6624 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 1 ms 344 KB Correct
2 Correct 0 ms 348 KB Correct
3 Correct 7 ms 2524 KB Correct
4 Correct 0 ms 348 KB Correct
5 Correct 9 ms 2780 KB Correct
6 Correct 9 ms 2776 KB Correct
7 Correct 1 ms 344 KB Correct
8 Correct 0 ms 348 KB Correct
9 Correct 2 ms 1116 KB Correct
10 Correct 0 ms 348 KB Correct
11 Correct 22 ms 2776 KB Correct
12 Correct 35 ms 860 KB Correct
13 Correct 412 ms 6596 KB Correct
14 Correct 455 ms 6532 KB Correct
15 Correct 1 ms 344 KB Correct
16 Correct 0 ms 348 KB Correct
17 Correct 214 ms 6556 KB Correct
18 Correct 217 ms 6600 KB Correct
19 Correct 399 ms 6600 KB Correct
20 Correct 163 ms 4560 KB Correct
21 Correct 183 ms 3936 KB Correct
22 Correct 414 ms 5372 KB Correct
23 Correct 368 ms 5572 KB Correct
24 Correct 415 ms 5580 KB Correct
25 Correct 386 ms 5292 KB Correct
26 Correct 1 ms 348 KB Correct
27 Correct 0 ms 348 KB Correct
28 Incorrect 1 ms 348 KB User solution is worse than jury's solution
29 Halted 0 ms 0 KB -