Submission #831026

#	Time	Username	Problem	Language	Result	Execution time	Memory
831026		vjudge1	Election (BOI18_election)	C++17	0 / 100	2 ms	468 KiB

election

#include <bits/stdc++.h>
using namespace std;

/// 123

class segtree_t {
       public:
        segtree_t *left, *right;
        int l, r, m, val, lazy;

        segtree_t(int l, int r) : l(l), r(r), m(l + r >> 1), val(0), lazy(0) {
                if (l == r) return;
                left = new segtree_t(l, m);
                right = new segtree_t(m + 1, r);
        }

        void Update(int s, int t, int x) {
                if (r < s or l > t) return;
                if (s <= l && r <= t) {
                        val += x;
                        lazy += x;
                        return;
                }
                Down();
                left->Update(s, t, x);
                right->Update(s, t, x);
                Up();
        }

        int Get(int s, int t) {
                if (r < s or l > t) return -1e9;
                if (s <= l && r <= t) return val;
                Down();
                return max(left->Get(s, t), right->Get(s, t));
        }

        void Up() {
                val = max(left->val, right->val);
        }

        void Down() {
                left->lazy += lazy;
                right->lazy += lazy;
                right->val += lazy;
                left->val += lazy;
                lazy = 0;
        }
};

template <class T>
class fenwick_t {
       public:
        vector<T> bit;
        int n;

        fenwick_t(int n = 0) : n(n) {
                bit.resize(n + 1, 0);
        }

        void Update(int pos, T val) {
                for (; pos <= n; pos += pos & -pos) {
                        bit[pos] += val;
                }
        }

        T Get(int pos) {
                T res = T(0);
                for (; pos > 0; pos -= pos & -pos) {
                        res += bit[pos];
                }
                return res;
        }

        T Get(int l, int r) {
                return Get(r) - (l ? Get(l - 1) : T(0));
        }
};

int32_t main() {
        ios_base::sync_with_stdio(0);
        cin.tie(0);
        int n, q;
        string s;
        cin >> n >> s >> q;
        vector<int> l(q), r(q);
        for (int i = 0; i < q; i++) {
                cin >> l[i] >> r[i];
                l[i]--, r[i]--;
        }
        vector<int> ord(q);
        iota(ord.begin(), ord.end(), 0);
        sort(ord.begin(), ord.end(), [&](int i, int j) {
                return r[i] < r[j];
        });
        priority_queue<int> pq;
        map<char, int> c;
        c['C'] = -1;
        c['T'] = +1;
        segtree_t *tree = new segtree_t(0, n);
        fenwick_t<int> cnt(n);
        for (int i = 0; i < n; i++) tree->Update(i + 1, n, c[s[i]]);
        vector<int> ans(q, -1);
        for (int i = 0, j = 0; i < n; i++) {
                if (s[i] == 'T') {
                        tree->Update(i + 1, n, -c[s[i]]);
                        pq.emplace(-i);
                        cnt.Update(i + 1, +1);
                } else {
                        if (pq.size()) {
                                tree->Update(-pq.top() + 1, n, c[s[-pq.top()]]);
                                cnt.Update(-pq.top() + 1, -1);
                                pq.pop();
                        }
                }
                while (j < q && r[ord[j]] == i) {
                        ans[ord[j]] = cnt.Get(l[ord[j]] + 1, r[ord[j]] + 1) + tree->Get(l[ord[j]], r[ord[j]] + 1) - tree->Get(l[ord[j]], l[ord[j]]);
                        j++;
                }
        }
        for (int i = 0; i < q; i++) cout << ans[i] << '\n';
}

Compilation message (stderr)

election.cpp: In constructor 'segtree_t::segtree_t(int, int)':
election.cpp:11:51: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   11 |         segtree_t(int l, int r) : l(l), r(r), m(l + r >> 1), val(0), lazy(0) {
      |                                                 ~~^~~

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