Submission #981875

#	Time	Username	Problem	Language	Result	Execution time	Memory
981875		LOLOLO	Election (BOI18_election)	C++17	100 / 100	762 ms	70580 KiB

election

#include <bits/stdc++.h>
#define ll long long
using namespace std;
 
#define           f     first
#define           s     second
#define           pb    push_back
#define           ep    emplace
#define           eb    emplace_back
#define           lb    lower_bound
#define           ub    upper_bound
#define       all(x)    x.begin(), x.end()
#define      rall(x)    x.rbegin(), x.rend()
#define   uniquev(v)    sort(all(v)), (v).resize(unique(all(v)) - (v).begin())
#define     mem(f,x)    memset(f , x , sizeof(f))
#define        sz(x)    (int)(x).size()
#define  __lcm(a, b)    (1ll * ((a) / __gcd((a), (b))) * (b))
#define          mxx    *max_element
#define          mnn    *min_element
#define    cntbit(x)    __builtin_popcountll(x)
#define       len(x)    (int)(x.length())
 
const int N = 1e6 + 30;
const int M = 5e5 + 5;
int cnt = 0;
int psum[N];
vector <pair <int, int>> ask[N];
int pos[N], n, ans[M];

struct seg{
    vector <int> laz, seg;
    void ass(int n) {
        laz.assign(n * 4 + 100, 0);
        seg.assign(n * 4 + 100, 0);
    }

    void push(int id) {
        int t = laz[id];
        laz[id * 2] += t;
        laz[id * 2 + 1] += t;
        seg[id * 2] += t;
        seg[id * 2 + 1] += t;
        laz[id] = 0;
    }

    void upd(int id, int l, int r, int u, int v, int c) {
        if (l > v || r < u)
            return;

        if (l >= u && r <= v) {
            seg[id] += c;
            laz[id] += c;
            return;
        }

        push(id);
        int m = (l + r) / 2;
        upd(id * 2, l, m, u, v, c);
        upd(id * 2 + 1, m + 1, r, u, v, c);
        seg[id] = max(seg[id * 2], seg[id * 2 + 1]);
    }

    int get(int id, int l, int r, int u, int v) {
        if (u == v && u == n + 1)
            return 0;

        if (l > v || r < u)
            return -1e9;

        if (l >= u && r <= v) {
            return seg[id];
        }

        push(id);
        int m = (l + r) / 2;
        return max(get(id * 2, l, m, u, v), get(id * 2 + 1, m + 1, r, u, v));
    }
};

struct fen{
    vector <int> f;
    int n;
    void ass(int N) {
        n = N;
        f.assign(n + 1, 0);
    }

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

    int get(int i) {
        int s = 0;
        for (; i; i -= i & (-i))
            s += f[i];

        return s;
    }

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

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    fen f;
    seg st;
    cin >> n;
    st.ass(n);
    f.ass(n);

    psum[0] = M;
    for (int i = 1; i <= n; i++) {
        char c;
        cin >> c;
        
        if (c == 'T') {
            st.upd(1, 1, n, 1, i, 1);
            psum[i]++;
        } else {
            psum[i]--;
            st.upd(1, 1, n, 1, i, -1);
        }

        psum[i] += psum[i - 1];
    }

    int q;
    cin >> q;
 
    for (int i = 1; i <= q; i++) {
        int l, r;
        cin >> l >> r;
        ask[l - 1].pb({r, i});
    }

    pos[psum[n]] = n;

    for (int i = n - 1; i >= 0; i--) {
        if (psum[i] < psum[i + 1]) {
            int p = pos[psum[i] + 1];
            st.upd(1, 1, n, 1, p, -1);
            f.upd(p, 1);
        } else {
            int p = pos[psum[i]];
            if (p) {
                st.upd(1, 1, n, 1, p, 1);
                f.upd(p, -1);
            }
        }

        pos[psum[i]] = i;
        for (auto x : ask[i]) {
            ans[x.s] = f.range(i + 1, x.f) + max(0, st.get(1, 1, n, i + 1, x.f) - st.get(1, 1, n, x.f + 1, x.f + 1));
        }
    }

    for (int i = 1; i <= q; i++) {
        cout << ans[i] << '\n';
    }

    return 0;
}  
  

• Subtask 1: 28 / 28
• Subtask 2: 54 / 54
• Subtask 3: 18 / 18