Submission #1059893

#	Time	Username	Problem	Language	Result	Execution time	Memory
1059893		Thanhs	Ekoeko (COCI21_ekoeko)	C++14	110 / 110	9 ms	6036 KiB

Main

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define int long long
// #define double long double
 
#define endl '\n'
#define fastIO ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
#define setmin(x, y) x = min((x), (y))
#define setmax(x, y) x = max((x), (y))
#define sqr(x) ((x) * (x))
#define fi first
#define se second
#define all(x) x.begin(), x.end()
 
// mt19937 hdp(chrono::high_resolution_clock::now().time_since_epoch().count());
// int rand(int l, int r){return l + ((hdp() % (r - l + 1)) + r - l + 1) % (r - l + 1);}

const int NM = 2e5 + 5;

int n, bit[NM], type[NM], cnt[NM], ans;
string s, ss[2];
queue<int> q[26];

void upd(int i)
{
    for (; i <= n; i += i & -i)
        bit[i]++;
}

int get(int i)
{
    int res = 0;
    for (; i; i -= i & -i)
        res += bit[i];
    return res;
}

int get(int l, int r)
{
    return get(r) - get(l - 1);
}

void solve()
{
    cin >> n >> s;
    n = s.size();
    for (char &c : s)
        c -= 'a';
    for (int i = 0; i < n; i++)
        cnt[s[i]]++;
    for (int i = 0; i < 26; i++)
        cnt[i] /= 2;
    int t = 0;
    for (int i = 0; i < n; i++)
    {
        type[i] = (cnt[s[i]] ? 0 : 1);
        ss[type[i]] += s[i];
        cnt[s[i]] = max(0ll, cnt[s[i]] - 1);
        if (!type[i]) 
            ans += t;
        else
            t++;
    }
    n /= 2;
    for (int i = 0; i < n; i++)
        q[ss[0][i]].push(i + 1);
    for (int i = 0; i < n; i++)
    {
        int a = q[ss[1][i]].front();
        q[ss[1][i]].pop();
        ans += get(a, n);
        upd(a);
    }
    cout << ans;
}

signed main()
{
    fastIO
    if (fopen("in.txt", "r")) 
    {
        freopen("in.txt", "r", stdin);
        freopen("out.txt", "w", stdout);
    }
    int tc = 1;
    // cin >> tc;
    while (tc--)
        solve();
}

Compilation message (stderr)

Main.cpp: In function 'void solve()':
Main.cpp:52:17: warning: array subscript has type 'char' [-Wchar-subscripts]
   52 |         cnt[s[i]]++;
      |                 ^
Main.cpp:58:28: warning: array subscript has type 'char' [-Wchar-subscripts]
   58 |         type[i] = (cnt[s[i]] ? 0 : 1);
      |                            ^
Main.cpp:60:17: warning: array subscript has type 'char' [-Wchar-subscripts]
   60 |         cnt[s[i]] = max(0ll, cnt[s[i]] - 1);
      |                 ^
Main.cpp:60:38: warning: array subscript has type 'char' [-Wchar-subscripts]
   60 |         cnt[s[i]] = max(0ll, cnt[s[i]] - 1);
      |                                      ^
Main.cpp:68:19: warning: array subscript has type 'char' [-Wchar-subscripts]
   68 |         q[ss[0][i]].push(i + 1);
      |                   ^
Main.cpp:71:27: warning: array subscript has type 'char' [-Wchar-subscripts]
   71 |         int a = q[ss[1][i]].front();
      |                           ^
Main.cpp:72:19: warning: array subscript has type 'char' [-Wchar-subscripts]
   72 |         q[ss[1][i]].pop();
      |                   ^
Main.cpp: In function 'int main()':
Main.cpp:84:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   84 |         freopen("in.txt", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:85:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   85 |         freopen("out.txt", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 40 / 40