Submission #692359

#	Time	Username	Problem	Language	Result	Execution time	Memory
692359		Farhan_HY	Ekoeko (COCI21_ekoeko)	C++14	10 / 110	215 ms	4644 KiB

Main

#include <bits/stdc++.h>
#define int long long
#define float double
#define pb push_back
#define F first
#define S second
#define T int t; cin >> t; while(t--)
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

using namespace std;
/// Benzema is the best player in the world
const int N = 1e6 + 6;
const int M = 1e3 + 3;
const int mod = 1e9 + 7;
const int inf = 1e9;
const int dx[] = {-1, 1, 0, 0};
const int dy[] = {0, 0, -1, 1};
const int LOG = 28;
int n, cnt[LOG], tree[N];
bool vis[N];
deque<int> pos[LOG];
string s;

void update(int node, int tl, int tr, int idx, int val) {
    if (tr == tl) {
        tree[node] += val;
        return;
    }
    int mid = (tr + tl) / 2;
    if (idx <= mid) update(2 * node, tl, mid, idx, val);
    else update(2 * node + 1, mid + 1, tr, idx, val);
    tree[node] = tree[2 * node] + tree[2 * node + 1];
}
void update(int idx, int val) {
    if (idx < n) update(1, 0, n - 1, idx, val);
}

int get(int node, int tl, int tr, int l, int r) {
    if (l <= tl && tr <= r) return tree[node];
    if (tr < l || tl > r) return 0;
    int mid = (tr + tl) / 2;
    int p1 = get(2 * node, tl, mid, l, r);
    int p2 = get(2 * node + 1, mid + 1, tr, l, r);
    return p1 + p2;
}
int get(int idx) {return get(1, 0, n - 1, 0, idx);}

main() {
    IOS
    cin >> n >> s;
    n *= 2;
    for(int i = 0; i < n; i++) cnt[s[i] - 'a']++, pos[s[i] - 'a'].push_back(i);
    for(int i = 0; i < 26; i++) cnt[i] /= 2;
    string s1, s2;
    int ans = 0;
    for(int i = 0; i < n / 2; i++) {
        int c = -1;
        for(int j = 0; j < 26; j++) {
            if (cnt[j] == 0 || pos[j].size() == 0) continue;
            if (c == -1 || pos[j].front() < pos[c].front()) c = j;
        }
        cnt[c]--;
        vis[pos[c].front()] = 1;
        ans += pos[c].front() - i;
        pos[c].pop_front();
        s1 += (c + 'a');
    }
    for(int i = 0; i < n; i++) if (!vis[i]) s2 += s[i];
    for(int i = 0; i < 26; i++) pos[i].clear();
    n /= 2;
    for(int i = 0; i < n; i++) pos[s2[i] - 'a'].push_back(i);
    for(int i = 0; i < n; i++) {
        int idx = pos[s1[i] - 'a'].front();
        idx += get(idx);
        ans += idx - i;
        pos[s1[i] - 'a'].pop_front();
        update(idx, -1);
        int l = 0, r = i;
        while(l < r) {
            int mid = (l + r + 1) / 2;
            if (mid + get(mid) <= i) l = mid;
            else r = mid - 1;
        }
        update(r, +1);
    }
    cout << ans;
}

Compilation message (stderr)

Main.cpp:48:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   48 | main() {
      | ^~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 40