Submission #198914

#	Time	Username	Problem	Language	Result	Execution time	Memory
198914		dimash241	Nivelle (COCI20_nivelle)	C++17	110 / 110	132 ms	21240 KiB

nivelle

# include <bits/stdc++.h>

# include <ext/pb_ds/assoc_container.hpp>
# include <ext/pb_ds/tree_policy.hpp>

using namespace __gnu_pbds;
using namespace std;
 
template<typename T> using ordered_set = tree <T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define _USE_MATH_DEFINES_
#define ll long long
#define ld long double
#define Accepted 0
#define pb push_back
#define mp make_pair
#define sz(x) (int)(x.size())
#define every(x) x.begin(),x.end()
#define F first
#define S second
#define lb lower_bound
#define ub upper_bound
#define For(i,x,y)  for (ll i = x; i <= y; i ++) 
#define FOr(i,x,y)  for (ll i = x; i >= y; i --)
#define SpeedForce ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
// ROAD to...                                                                                                                                                                                                                Red

inline void Input_Output () {
	//freopen(".in", "r", stdin);
   //freopen(".out", "w", stdout);
}

const double eps = 0.000001;
const ld pi = acos(-1);
const int maxn = 1e7 + 9;
const int mod = 1e9 + 7;
const ll MOD = 1e18 + 9;
const ll INF = 1e18 + 123;
const int inf = 2e9 + 11;
const int mxn = 1e6 + 9;
const int N = 6e5 + 123;                                          
const int M = 26;
const int pri = 997;
const int Magic = 2101;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, -1, 0, 1};
 
int n;
int a[N];
int u[M];
int pre[N][M];
int nxt[N][M];
int f[N];
int c[N], ret;

void add (int x) {
	u[x]++;
	if(u[x] == 1) ret++;
}

void rem (int x) {	
	u[x] --;
	if (!u[x]) ret--;
}

int main () {
	SpeedForce;
	cin >> n;

	for (int i = 1; i <= n; i ++) {
		char ch;
		cin >> ch;
		a[i] = ch - 'a';
	}
	for (int i = 0; i < M; i ++) {
		nxt[n+1][i] = n + 1;
	}

	for (int i = 1; i <= n; i ++) {
		for (int j = 0; j < 26; ++j)
			pre[i][j] = pre[i-1][j];
		pre[i][a[i]] = i;
	}

	for (int i = n; i >= 1; i --) {
		for (int j = 0; j < 26; ++j)
			nxt[i][j] = nxt[i+1][j];
		nxt[i][a[i]] = i;
	}

	double res = 1;
	pair < int, int > ans = mp(1, 1);
	for (int i = 1; i <= n; i ++) {
		vector < int > pref;
		for (int j = 0; j < 26; j ++) {
			u[j] = 0;
			pref.pb(pre[i][j]);
		}
		sort(pref.rbegin(), pref.rend());
		ret = 0;
		for (int j = 0; j < pref.size(); j++) {
			if (!pref[j]) break;
			int l = 0, r = i + 1;
			if (j + 1 < pref.size()) l = pref[j+1];
			add(a[pref[j]]);
			double now = ret;
			now /= (r - l - 1);

			if (now < res) {
				res = now;
				ans = mp(l + 1, r - 1);
			}
		}
	}
	cout << ans.F << ' ' << ans.S << '\n';
	return Accepted;
}

// B...a

Compilation message (stderr)

nivelle.cpp: In function 'int main()':
nivelle.cpp:102:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int j = 0; j < pref.size(); j++) {
                   ~~^~~~~~~~~~~~~
nivelle.cpp:105:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if (j + 1 < pref.size()) l = pref[j+1];
        ~~~~~~^~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 17 / 17
• Subtask 3: 13 / 13
• Subtask 4: 25 / 25
• Subtask 5: 48 / 48