Submission #611784

#	Time	Username	Problem	Language	Result	Execution time	Memory
611784		tengiz05	Election (BOI18_election)	C++17	100 / 100	1250 ms	53036 KiB

election

#include <bits/stdc++.h>

using i64 = long long;
using namespace std;

constexpr int inf = 1E9;

struct Info {
    int x;
    Info(int x = -inf) : x(x) {}
};
Info operator+(const Info &a, const Info &b) {
    return Info(max(a.x, b.x));
}
struct Tag {
    int x;
    Tag(int x = 0) : x(x) {}
};
void apply(Tag &a, const Tag &b) {
    a.x += b.x;
}
void apply(Info &a, const Tag &b) {
    a.x += b.x;
}
template<class Info, class Tag,
    class Merge = std::plus<Info>>
struct LazySegmentTree {
    const int n;
    const Merge merge;
    std::vector<Info> info;
    std::vector<Tag> tag;
    LazySegmentTree(int n) : n(n), merge(Merge()), info(4 << std::__lg(n)), tag(4 << std::__lg(n)) {}
    LazySegmentTree(std::vector<Info> init) : LazySegmentTree(init.size()) {
        std::function<void(int, int, int)> build = [&](int p, int l, int r) {
            if (r - l == 1) {
                info[p] = init[l];
                return;
            }
            int m = (l + r) / 2;
            build(2 * p, l, m);
            build(2 * p + 1, m, r);
            pull(p);
        };
        build(1, 0, n);
    }
    void pull(int p) {
        info[p] = merge(info[2 * p], info[2 * p + 1]);
    }
    void apply(int p, const Tag &v) {
        ::apply(info[p], v);
        ::apply(tag[p], v);
    }
    void push(int p) {
        apply(2 * p, tag[p]);
        apply(2 * p + 1, tag[p]);
        tag[p] = Tag();
    }
    void modify(int p, int l, int r, int x, Info v) {
        if (r - l == 1) {
            info[p] = v;
            return;
        }
        int m = (l + r) / 2;
        push(p);
        if (x < m) {
            modify(2 * p, l, m, x, v);
        } else {
            modify(2 * p + 1, m, r, x, v);
        }
        pull(p);
    }
    void modify(int x, Info v) {
        modify(1, 0, n, x, v);
    }
    Info rangeQuery(int p, int l, int r, int x, int y) {
        if (l >= y || r <= x) {
            return Info();
        }
        if (l >= x && r <= y) {
            return info[p];
        }
        int m = (l + r) / 2;
        push(p);
        return merge(rangeQuery(2 * p, l, m, x, y), rangeQuery(2 * p + 1, m, r, x, y));
    }
    Info rangeQuery(int l, int r) {
        return rangeQuery(1, 0, n, l, r);
    }
    void rangeApply(int p, int l, int r, int x, int y, const Tag &v) {
        if (l >= y || r <= x) {
            return;
        }
        if (l >= x && r <= y) {
            apply(p, v);
            return;
        }
        int m = (l + r) / 2;
        push(p);
        rangeApply(2 * p, l, m, x, y, v);
        rangeApply(2 * p + 1, m, r, x, y, v);
        pull(p);
    }
    void rangeApply(int l, int r, const Tag &v) {
        return rangeApply(1, 0, n, l, r, v);
    }
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int n;
    cin >> n;
    
    string S;
    cin >> S;
    
    int q;
    cin >> q;
    
    vector<vector<pair<int, int>>> Q(n);
    vector<int> ans(q);
    
    for (int i = 0; i < q; i++) {
        int l, r;
        cin >> l >> r;
        l--;
        r--;
        Q[l].emplace_back(r, i);
    }
    
    stack<int> s;
    
    LazySegmentTree<Info, Tag> res(n), f(n);
    
    for (int i = 0; i < n; i++) {
        res.modify(i, Info(0));
        f.modify(i, Info(0));
    }
    
    for (int i = n - 1; i >= 0; i--) {
        if (S[i] == 'T') {
            res.rangeApply(i, n, 1);
            s.push(i);
        } else {
            if (!s.empty()) {
                res.rangeApply(s.top(), n, -1);
                f.rangeApply(s.top(), n, -1);
                s.pop();
            }
            f.rangeApply(i, n, 1);
        }
        for (auto [r, id] : Q[i]) {
            ans[id] = res.rangeQuery(r, r + 1).x + (f.rangeQuery(i, r + 1).x - f.rangeQuery(r, r + 1).x);
        }
    }
    
    for (int i = 0; i < q; i++) {
        cout << ans[i] << "\n";
    }
    
    return 0;
}

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