oj.uz

Submission #674595

# Submission time Handle Problem Language Result Execution time Memory
674595 2022-12-25T08:42:58 Z esomer Watching (JOI13_watching) C++17
100 / 100
 375 ms 15476 KB 
#include<bits/stdc++.h>
 
using namespace std;
 
#define ll long long
#define endl "\n"
 
const int MOD = 998244353;

void solve(){
	int n, p, q; cin >> n >> p >> q;
	swap(p, q);
	vector<int> v(n);
	for(auto &i : v) cin >> i;
	sort(v.begin(), v.end());
	if(n <= p + q){
		cout << 1 << endl; return;
	}
	set<pair<int, int>> s;
	for(int i = 0; i < n; i++) s.insert({v[i], i});
	int ans;
	ll lo = 1;
	ll hi = 1e9;
	while(lo <= hi){
		ll w = (lo + hi) / 2;
		vector<vector<int>> dp(n, vector<int>(p + 1, 1e9));
		for(int i = 0; i < n; i++){
			auto it = s.upper_bound({v[i] - w, 1e9});
			if(it == s.begin()){
				dp[i] = vector<int>(p + 1, 1);
			}else{
				it--;
				int j = (*it).second;
				dp[i] = dp[j];
				for(int g = 0; g <= p; g++) dp[i][g]++;
			}
			it = s.upper_bound({v[i] - 2 * w, 1e9});
			if(it == s.begin()){
				for(int g = 1; g <= p; g++) dp[i][g] = 0;
			}else{
				it--;
				int j = (*it).second;
				for(int g = 1; g <= p; g++){
					dp[i][g] = min(dp[i][g], dp[j][g - 1]);
				}
			}
		}
		if(dp[n - 1][p] <= q){
			ans = w;
			hi = w - 1;
		}else lo = w + 1;
	}
	cout << ans << endl;
}
 
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
 
    //freopen("inpt.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);
 
    //int tt; cin >> tt;
    int tt = 1;
    for(int t = 1; t <= tt; t++){
        solve();
    }
}

Compilation message

watching.cpp: In function 'void solve()':
watching.cpp:6:14: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
    6 | #define endl "\n"
      |              ^~~~
watching.cpp:21:6: note: 'ans' was declared here
   21 |  int ans;
      |      ^~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 316 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 316 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 320 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 212 KB Output is correct
14 Correct 1 ms 316 KB Output is correct
15 Correct 1 ms 212 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 536 KB Output is correct
2 Correct 1 ms 300 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 328 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 7 ms 596 KB Output is correct
8 Correct 142 ms 6452 KB Output is correct
9 Correct 27 ms 1576 KB Output is correct
10 Correct 22 ms 1244 KB Output is correct
11 Correct 375 ms 15476 KB Output is correct
12 Correct 198 ms 8232 KB Output is correct
13 Correct 10 ms 596 KB Output is correct
14 Correct 9 ms 608 KB Output is correct
15 Correct 11 ms 644 KB Output is correct