Submission #844484

#	Time	Username	Problem	Language	Result	Execution time	Memory
844484		vjudge1	Nivelle (COCI20_nivelle)	C++17	62 / 110	1032 ms	21080 KiB

nivelle

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
using namespace std;
#define int long long

#define ONLINE_JUDGE
#ifndef ONLINE_JUDGE
    #define OPEN freopen(".in", "r", stdin); \
                 freopen(".out", "w", stdout);
#else
    #define OPEN void(23);
#endif

void solve1(int n, string str)
{
    str = '$' + str;

    double ans = 2;
    pair <int, int> cev;
    int l = 1, r = 1;
    while(r <= n && l <= n)
    {
        if(r + 1 <= n && str[r +1] == str[l]) r++;
        else
        {
            l = r +1;
            continue;
        }


        double calc = double(1.0f) / (r - l +1);
        if(calc < ans)
        {
            ans = calc;
            cev = {l, r};
        }
    }

    bool ok = true;
    for(int i = 1; i +1 <= n; i++) ok &= str[i] == str[i +1];

    if(!ok)
    {
        double calc = double(2.0f) / n;
        if(calc < ans)
        {
            ans = calc;
            cev = {1, n};
        }
    }

    cerr << 'T' << ans;
    cout << cev.first << " " << cev.second;

    return;
}

void solve2(int n, string str)
{
    str = '$' + str;

    vector <array <int, 26>> pref(n +1);
    for(int i = 0; i < 26; i++) pref[0][i] = 0;
    for(int i = 1; i <= n; i++)
    {
        pref[i] = pref[i -1];
        pref[i][str[i] - 'a']++;
    }

    long double ans = 2;
    pair <int, int> inds;
    for(int l = 1; l <= n; l++)
    {
        for(int r = l; r <= n; r++)
        {
            array <int, 26> c;
            int tot = 0;
            for(int i = 0; i < 26; i++) 
                c[i] = pref[r][i] - pref[l -1][i], tot += (c[i] != 0);

            long double cost = tot;
            cost /= (r - l +1);
            //cerr << l << " " << r << " " << cost << "\n";
            if(cost < ans)
            {
                ans = cost;
                inds = {l, r};
            }
        }
    }

    cout << inds.first << " " << inds.second << "\n";

    return;
}

int arr[256];

int find(int x)
{
    int res = 0;
    while(x) res += (x & 1), x /= 2;

    return res;
}

int check(int a, int b)
{
    bool ok = true;
    for(int i = 5; i >= 1; i--)
    {
        if(b & 1)
        {
            ok &= (a & 1);
        }

        b >>= 1;
        a >>= 1;
    }

    return ok;
}

void solve3(int n, string str)
{
    str = '$' + str;

    arr['a'] = 1;
    arr['b'] = 2;
    arr['c'] = 4;
    arr['d'] = 8;
    arr['e'] = 16;

    double ans = 1;
    pair <int, int> cev = {1, 1};
    for(int i = 0; i < (1 << 5); i++)
    {
        //cerr << i << " ";
        int l = 1, r = 1;
        while(r <= n && l <= n)
        {
            //cerr << l << " " << r << "\n";
            if(!check(i, arr[str[l]]))
            {
                l++;
                r++;
                continue;
            }
            if(r + 1 <= n && check(i, arr[str[r +1]])) r++;
            else
            {
                l = r +1;
                r++;
                continue;
            }

            double calc = double(find(i)) / (r - l +1);
            if(l == 2 && r == 19) cerr << calc;
            if(calc < ans)
            {
                ans = calc;
                cev = {l, r};
            }
        }
    }

    cerr << ans;
    cout << cev.first << " " << cev.second << "\n";
}

int32_t main()
{
    OPEN;

    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    
    int n; string str; cin >> n >> str; 
    int cnta = count(str.begin(), str.end(), 'a');
    int cntb = count(str.begin(), str.end(), 'b');
    int cntc = count(str.begin(), str.end(), 'c');
    int cntd = count(str.begin(), str.end(), 'd');
    int cnte = count(str.begin(), str.end(), 'e');

    if(cnta + cntb == n) solve1(n, str);
    else if(cnta + cntb + cntc + cntd + cnte == n) solve3(n, str);
    else solve2(n, str);
}

Compilation message (stderr)

nivelle.cpp: In function 'void solve3(long long int, std::string)':
nivelle.cpp:144:36: warning: array subscript has type 'char' [-Wchar-subscripts]
  144 |             if(!check(i, arr[str[l]]))
      |                                    ^
nivelle.cpp:150:52: warning: array subscript has type 'char' [-Wchar-subscripts]
  150 |             if(r + 1 <= n && check(i, arr[str[r +1]])) r++;
      |                                                    ^

• Subtask 1: 7 / 7
• Subtask 2: 17 / 17
• Subtask 3: 13 / 13
• Subtask 4: 25 / 25
• Subtask 5: 0 / 48