Submission #479647

#	Time	Username	Problem	Language	Result	Execution time	Memory
479647		CodeChamp_SS	Election (BOI18_election)	C++17	0 / 100	7 ms	460 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, pre[N], suf[N];
string s;

struct SegTree {
    ll st[4 * N]{}, lazy[4 * N]{};
    ll dummy = inf;

    ll combine(ll l, ll r) {
        return min(l, r);
    }

    void pushDown(ll s, ll e, int idx) {
        st[idx] += lazy[idx];
        if (s != e) lazy[2 * idx] += lazy[idx], lazy[2 * idx + 1] += lazy[idx];
        lazy[idx] = 0;
    }

    void build(ll *a, ll s = 1, ll e = n, int idx = 1) {
        if (s == e) {
            st[idx] = a[s];
            return;
        }

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

    void updateLazy(ll qs, ll qe, ll val, ll s = 1, ll e = n, int idx = 1) {
        if (lazy[idx] != 0) pushDown(s, e, idx);

        if (qs > e or qe < s) return;

        if (s >= qs and e <= qe) {
            lazy[idx] += val;
            pushDown(s, e, idx);
            return;
        }

        ll mid = s + (e - s) / 2;
        updateLazy(qs, qe, val, s, mid, 2 * idx), updateLazy(qs, qe, val, mid + 1, e, 2 * idx + 1);
        st[idx] = combine(st[2 * idx], st[2 * idx + 1]);
    }

    ll query(ll qs, ll qe, ll s = 1, ll e = n, int idx = 1) {
        if (lazy[idx] != 0) pushDown(s, e, idx);

        if (qs > e or qe < s) return dummy;

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

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

int main() {
    fio();

    cin >> n >> s >> q;

    rep1(x, n) pre[x] = pre[x - 1] + ((s[x - 1] == 'C') ? 1 : -1);
    rrep1(x, n) suf[x] = suf[x + 1] + ((s[x - 1] == 'C') ? 1 : -1);

    st_pre.build(pre), st_suf.build(suf);
    rep0(x, q) {
        int l, r;
        cin >> l >> r;
        ll prv = pre[l - 1], nxt = suf[r + 1];
        ll cur = 0;
        int i = l, j = r, k = -1;
        while (i <= j) {
            int m = (i + j) / 2;
            if (st_pre.query(m, m) - prv == -(m - l + 1)) k = m, i = m + 1;
            else j = m - 1;
        }
        if (k != -1) {
            cur += abs(st_pre.query(k, k) - prv);
            if (k == r) {
                cout << cur << '\n';
                continue;
            }
            l = k + 1, prv = pre[k];
        }
        i = l, j = r, k = -1;
        while (i <= j) {
            int m = (i + j) / 2;
            if (st_suf.query(m, m) - nxt == -(r - m + 1)) k = m, j = m - 1;
            else i = m + 1;
        }
        if (k != -1) {
            cur += abs(st_suf.query(k, k) - nxt);
            r = k - 1, nxt = suf[k];
        }
        ll nw = min(st_pre.query(l, r) - prv, st_suf.query(l, r) - nxt);
        if (nw < 0) cur += abs(nw);
        cout << cur << '\n';
    }

    return 0;
}

• Subtask 1: 0 / 28
• Subtask 2: 0 / 54
• Subtask 3: 0 / 18