Submission #479648

#	Time	Username	Problem	Language	Result	Execution time	Memory
479648		CodeChamp_SS	Election (BOI18_election)	C++17	100 / 100	564 ms	28104 KiB

election

#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;

#define ff                  first
#define ss                  second
#define pb                  push_back
#define eb                  emplace_back
#define mp                  make_pair
#define lb                  lower_bound
#define ub                  upper_bound
#define setbits(x)          __builtin_popcountll(x)
#define zrobits(x)          __builtin_ctzll(x)
#define sz(v)               (int)v.size()
#define ps(y)               cout << fixed << setprecision(y)
#define ms(arr, v)          memset(arr, v, sizeof(arr))
#define all(v)              v.begin(), v.end()
#define rall(v)             v.rbegin(), v.rend()
#define trav(x, v)          for(auto &x: v)
#define w(t)                int t; cin >> t; while(t--)
#define rep(i, a, b)        for(int i = a; i <= b; i++)
#define rrep(i, a, b)       for(int i = a; i >= b; i--)
#define rep0(i, n)          rep(i, 0, n - 1)
#define rrep0(i, n)         rrep(i, n - 1, 0)
#define rep1(i, n)          rep(i, 1, n)
#define rrep1(i, n)         rrep(i, n, 1)
#define inp(arr, n)         rep0(i, n) cin >> arr[i];

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> pii;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef vector<pii> vp;
typedef vector<bool> vb;
typedef vector<string> vs;
typedef map<ll, ll> mii;
typedef map<char, ll> mci;
typedef priority_queue<ll> pq_mx;
typedef priority_queue<ll, vi, greater<>> pq_mn;
typedef tree<ll, null_type, less<>, rb_tree_tag, tree_order_statistics_node_update> pbds;
/*
 * find_by_order(i) -> returns an iterator to the element at ith position (0 based)
 * order_of_key(i)  -> returns the position of element i (0 based)
 */

const int N = 5e5 + 5;
const int mod = 1e9 + 7;
//const int mod = 998244353;
const ll inf = 2e18;
const ld eps = 1e-10, pi = acos(-1.0);

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void fio() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
}

ll n, q;
string S;

struct Node {
    int lmx = 0, rmx = 0, sum = 0, mx = 0;
};

struct SegTree {
    Node st[4 * N]{}, dummy{};

    Node combine(Node l, Node r) {
        return {
                max(l.lmx, l.sum + r.lmx),
                max(r.rmx, r.sum + l.rmx),
                l.sum + r.sum,
                max(l.lmx + r.rmx, max(l.mx + r.sum, l.sum + r.mx))
        };
    }

    void build(ll s = 0, ll e = n - 1, int idx = 1) {
        if (s == e) {
            st[idx] = ((S[s] == 'T') ? Node{1, 1, 1, 1} : Node{0, 0, -1, 0});
            return;
        }

        ll m = s + (e - s) / 2;
        build(s, m, 2 * idx), build(m + 1, e, 2 * idx + 1);
        st[idx] = combine(st[2 * idx], st[2 * idx + 1]);
    }

    Node query(ll qs, ll qe, ll s = 0, ll e = n - 1, int idx = 1) {
        if (qs > e or qe < s) return dummy;

        if (s >= qs and e <= qe) return st[idx];

        ll mid = s + (e - s) / 2;
        Node lft = query(qs, qe, s, mid, 2 * idx), rt = query(qs, qe, mid + 1, e, 2 * idx + 1);
        return combine(lft, rt);
    }
} st;

int main() {
    fio();

    cin >> n >> S >> q;

    st.build();
    rep0(x, q) {
        int l, r;
        cin >> l >> r, --l, --r;
        cout << st.query(l, r).mx << '\n';
    }

    return 0;
}

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