Submission #601010

#	Time	Username	Problem	Language	Result	Execution time	Memory
601010		KoD	Fish 2 (JOI22_fish2)	C++17	100 / 100	711 ms	18244 KiB

fish2

#include <bits/stdc++.h>
 
using ll = long long;
using std::pair;
using std::vector;
 
class Sequence {
    struct Data {
        int max;
        ll sum;
        static Data identity() {
            return {0, 0};
        }
        static Data make(const int x) {
            return {x, x};
        }
        friend Data operator+(const Data& l, const Data& r) {
            return {std::max(l.max, r.max), l.sum + r.sum};
        }
    };
 
    int size, logn;
    vector<Data> data;
 
  public:
    explicit Sequence(const vector<int>& vec) {
        logn = 0;
        while ((1 << logn) < (int)vec.size()) {
            logn += 1;
        }
        size = 1 << logn;
        data.resize(2 * size, Data::identity());
        for (int i = 0; i < (int)vec.size(); ++i) {
            data[size + i] = Data::make(vec[i]);
        }
        for (int i = size - 1; i > 0; --i) {
            data[i] = data[2 * i] + data[2 * i + 1];
        }
    }
 
    void update(int i, const int x) {
        i += size;
        data[i] = Data::make(x);
        while (i > 1) {
            i >>= 1;
            data[i] = data[2 * i] + data[2 * i + 1];
        }
    }
 
    ll sum(int l, int r) const {
        l += size;
        r += size;
        ll ret = 0;
        while (l < r) {
            if (l & 1) {
                ret += data[l].sum;
                l += 1;
            }
            if (r & 1) {
                r -= 1;
                ret += data[r].sum;
            }
            l >>= 1;
            r >>= 1;
        }
        return ret;
    }
 
    int upb_to_right(int l, const ll x) {
        if (l == size) return -1;
        l += size;
        do {
            while (!(l & 1)) l >>= 1;
            if (data[l].max > x) {
                while (l < size) {
                    l <<= 1;
                    if (data[l].max <= x) {
                        l += 1;
                    }
                }
                return l - size;
            }
            l >>= 1;
            l += 1;
        } while (l & (l - 1));
        return -1;
    }
 
    int upb_to_left(int r, const ll x) {
        if (r == 0) return -1;
        r += size;
        do {
            while (!(r & 1)) r >>= 1;
            r -= 1;
            if (data[r].max > x) {
                while (r < size) {
                    r <<= 1;
                    if (data[r + 1].max > x) {
                        r += 1;
                    }
                }
                return r - size;
            }
            r >>= 1;
        } while (r & (r - 1));
        return -1;
    }
};
 
class Intervals {
    int size, logn;
    vector<vector<pair<int, int>>> data;
 
  public:
    explicit Intervals(const int n) {
        logn = 0;
        while ((1 << logn) < n) {
            logn += 1;
        }
        size = 1 << logn;
        data.resize(2 * size);
    }
  
    void add(const int l, const int r) {
        int i = l + size, j = l + 1, k = 1;
        while (j < r) {
            if (!(i & 1)) {
                j += k;
            }
            i >>= 1;
            k <<= 1;
        }
        data[i].emplace_back(l, r);
    }
 
    template <class F>
    void pop(const int k, const F& f) {
        int i = k + size;
        while (i > 0) {
            auto& vec = data[i];
            for (int i = 0; i < (int)vec.size();) {
                const auto& [l, r] = vec[i];
                if (l <= k and k < r) {
                    f(l, r);
                    std::swap(vec[i], vec.back());
                    vec.pop_back();
                } else {
                    i += 1;
                }
            }
            i >>= 1;
        }
    }
};
 
class SegmentTree {
    struct Data {
        int min, cnt;
        static Data identity() {
            return {1000000000, 0};
        }
        static Data make(const int x) {
            return {x, 1};
        }
        friend Data operator+(const Data& l, const Data& r) {
            const int m = std::min(l.min, r.min);
            return {m, (l.min == m ? l.cnt : 0) + (r.min == m ? r.cnt : 0)};
        }
    };
 
    int size, logn;
    vector<Data> data;
    vector<int> add;
 
    void apply(const int k, const int a) {
        data[k].min += a;
        if (k < size) {
            add[k] += a;
        }
    }
    void flush(const int k) {
        if (add[k] != 0) {
            apply(2 * k, add[k]);
            apply(2 * k + 1, add[k]);
            add[k] = 0;
        }
    }
    void push(const int k) {
        const int lsb = __builtin_ctz(k);
        for (int d = logn; d > lsb; --d) {
            flush(k >> d);
        }
    }
 
    void fetch(const int k) {
        data[k] = data[2 * k] + data[2 * k + 1];
    }
    void pull(int k) {
        k >>= __builtin_ctz(k);
        while (k > 1) {
            fetch(k >>= 1);
        }
    }
 
  public:
    explicit SegmentTree(const int n) {
        logn = 0;
        while ((1 << logn) < n) {
            logn += 1;
        }
        size = 1 << logn;
        data.resize(2 * size, Data::identity());
        for (int i = 0; i < n; ++i) {
            data[size + i] = Data::make(0);
        }
        for (int i = size - 1; i > 0; --i) {
            data[i] = data[2 * i] + data[2 * i + 1];
        }
        add.resize(size);
    }
 
    void operate(int l, int r, const int x) {
        l += size;
        r += size;
        push(l);
        push(r);
        const int lc = l, rc = r;
        while (l < r) {
            if (l & 1) {
                apply(l, x);
                l += 1;
            }
            if (r & 1) {
                r -= 1;
                apply(r, x);
            }
            l >>= 1;
            r >>= 1;
        }
        pull(lc);
        pull(rc);
    }
 
    int fold(int l, int r) {
        l += size;
        r += size;
        push(l);
        push(r);
        Data ret = Data::identity();
        while (l < r) {
            if (l & 1) {
                ret = ret + data[l];
                l += 1;
            }
            if (r & 1) {
                r -= 1;
                ret = data[r] + ret;
            }
            l >>= 1;
            r >>= 1;
        }
        return ret.cnt;
    }
};
 
int main() {
    int N;
    std::cin >> N;
    vector<int> A(N);
    for (auto& x : A) {
        std::cin >> x;
    }
    Sequence seq(A);
    Intervals range(N);
    SegmentTree seg(N);
    const auto insert = [&](int l, int r) {
        if (l + 1 < r) {
            seg.operate(l + 1, r, 1);
            range.add(l, r + 1);
        }
    };
    const auto erase = [&](const int l, const int r) {
        seg.operate(l + 1, r - 1, -1);
    };
    {
        vector<ll> accum(N + 1);
        for (int i = 0; i < N; ++i) {
            accum[i + 1] = accum[i] + A[i];
        }
        vector<int> stack;
        const auto test = [&](const int l, const int r) {
            if (std::min(A[l], A[r]) > accum[r] - accum[l + 1]) {
                insert(l, r);
            }
        };
        for (int i = 0; i < N; ++i) {
            while (!stack.empty() and A[stack.back()] < A[i]) {
                test(stack.back(), i);
                stack.pop_back();
            }
            if (!stack.empty()) {
                test(stack.back(), i);
            }
            stack.push_back(i);
        }
    }
    int Q;
    std::cin >> Q;
    while (Q--) {
        int t;
        std::cin >> t;
        if (t == 1) {
            int i, x;
            std::cin >> i >> x;
            i -= 1;
            A[i] = x;
            seq.update(i, x);
            range.pop(i, erase);
            vector<pair<int, ll>> left, right;
            {
                int k = i + 1;
                ll sum = 0;
                while (k < N) {
                    right.emplace_back(k, seq.sum(i + 1, k));
                    sum += A[k];   
                    k = seq.upb_to_right(k + 1, sum);
                    if (k == -1) {
                        break;
                    }
                } 
            }
            {
                int k = i - 1;
                ll sum = 0;
                while (k >= 0) {
                    left.emplace_back(k, seq.sum(k + 1, i));
                    sum += A[k];   
                    k = seq.upb_to_left(k, sum);
                    if (k == -1) {
                        break;
                    }
                } 
            }
            for (const auto& [l, sl] : left) {
                if (std::min(A[i], A[l]) > sl) {
                    insert(l, i);
                }
            }
            for (const auto& [r, sr] : right) {
                if (std::min(A[i], A[r]) > sr) {
                    insert(i, r);
                }
            }
            for (const auto& [l, sl] : left) {
                for (const auto& [r, sr] : right) {
                    if (std::min(A[l], A[r]) > sl + A[i] + sr) {
                        insert(l, r);
                    }
                }
            }
        } else {
            int l, r;
            std::cin >> l >> r;
            l -= 1;
            {
                ll sum = 0;
                const int lc = l;
                int cand = l;
                while (true) {
                    sum += A[l];
                    const int k = seq.upb_to_right(l + 1, sum);
                    if (k == -1 or k >= r) {
                        break;
                    }
                    if (seq.sum(lc, k) < A[k]) {
                        cand = k;
                    }
                    l = k;
                }
                l = cand;
            }
            {
                ll sum = 0;
                const int rc = r;
                int cand = r;
                while (true) {
                    sum += A[r - 1];
                    const int k = seq.upb_to_left(r - 1, sum);
                    if (k == -1 or k < l) {
                        break;
                    }
                    if (seq.sum(k + 1, rc) < A[k]) {
                        cand = k + 1;
                    }
                    r = k + 1;
                }
                r = cand;
            }
            std::cout << seg.fold(l, r) << '\n';
        } 
    }
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 12 / 12
• Subtask 4: 23 / 23
• Subtask 5: 35 / 35
• Subtask 6: 17 / 17