Submission #943604

#	Time	Username	Problem	Language	Result	Execution time	Memory
943604		Pannda	Fish 2 (JOI22_fish2)	C++17	8 / 100	4070 ms	8856 KiB

fish2

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

struct Paint {
    struct Node {
        int mn, cnt;
        int lazy = 0;
        void add(int delta) {
            mn += delta;
            lazy += delta;
        }
        void merge(Node a, Node b) {
            mn = min(a.mn, b.mn);
            cnt = 0;
            if (a.mn == mn) cnt += a.cnt;
            if (b.mn == mn) cnt += b.cnt;
        }
    };

    int n;
    vector<Node> nodes;

    Paint(int n) : n(n), nodes(4 * n) {
        auto dfs = [&](auto self, int idx, int l, int r) -> void {
            if (l + 1 == r) {
                nodes[idx].mn = 0;
                nodes[idx].cnt = 1;
            } else {
                int m = (l + r) >> 1;
                self(self, 2 * idx + 1, l, m);
                self(self, 2 * idx + 2, m, r);
                nodes[idx].merge(nodes[2 * idx + 1], nodes[2 * idx + 2]);
            }
        };
        dfs(dfs, 0, 0, n);
    }

    void down(int idx) {
        nodes[2 * idx + 1].add(nodes[idx].lazy);
        nodes[2 * idx + 2].add(nodes[idx].lazy);
        nodes[idx].lazy = 0;
    }

    void add(int ql, int qr, int delta) {
        auto dfs = [&](auto self, int idx, int l, int r) -> void {
            if (r <= ql || qr <= l) return;
            if (ql <= l && r <= qr) return nodes[idx].add(delta);
            down(idx);
            int m = (l + r) >> 1;
            self(self, 2 * idx + 1, l, m);
            self(self, 2 * idx + 2, m, r);
            nodes[idx].merge(nodes[2 * idx + 1], nodes[2 * idx + 2]);
        };
        dfs(dfs, 0, 0, n);
    }

    int countZero(int ql, int qr) {
        int fetch = 0;
        auto dfs = [&](auto self, int idx, int l, int r) -> void {
            if (r <= ql || qr <= l) return;
            if (ql <= l && r <= qr) {
                fetch += nodes[idx].mn == 0 ? nodes[idx].cnt : 0;
                return;
            }
            down(idx);
            int m = (l + r) >> 1;
            self(self, 2 * idx + 1, l, m);
            self(self, 2 * idx + 2, r, m);
        };
        dfs(dfs, 0, 0, n);
        return fetch;
    }
};

struct SegmentWalk {
    int n;
    vector<int> mx;

    SegmentWalk(int n) : n(n), mx(4 * n, 0) {}

    void set(int i, int val) {
        auto dfs = [&](auto self, int idx, int l, int r) -> void {
            if (l + 1 == r) {
                mx[idx] = val;
            } else {
                int m = (l + r) >> 1;
                if (i < m) self(self, 2 * idx + 1, l, m);
                else self(self, 2 * idx + 2, m, r);
                mx[idx] = max(mx[2 * idx + 1], mx[2 * idx + 2]);
            }
        };
        dfs(dfs, 0, 0, n);
    }

    int walk(int ql, int qr, long long bound, bool request_leftmost) { // in [ql, qr), returns the leftmost (rightmost) position with value > 'bound'
        auto dfs = [&](auto self, int idx, int l, int r) -> int {
            if (r <= ql || qr <= l || mx[idx] <= bound) return -1;
            if (ql <= l && r <= qr) {
                while (l + 1 < r) {
                    int m = (l + r) >> 1;
                    if (request_leftmost) {
                        if (mx[2 * idx + 1] > bound) idx = 2 * idx + 1, r = m;
                        else idx = 2 * idx + 2, l = m;
                    } else {
                        if (mx[2 * idx + 2] > bound) idx = 2 * idx + 2, l = m;
                        else idx = 2 * idx + 1, r = m;
                    }
                }
                return l;
            }
            int m = (l + r) >> 1;
            if (request_leftmost) {
                int get = self(self, 2 * idx + 1, l, m);
                if (get != -1) return get;
                return self(self, 2 * idx + 2, m, r);
            } else {
                int get = self(self, 2 * idx + 2, m, r);
                if (get != -1) return get;
                return self(self, 2 * idx + 1, l, m);
            }
        };
        return dfs(dfs, 0, 0, n);
    }
};

struct Fenwick {
    int n;
    vector<long long> bit;

    Fenwick(int n) : n(n), bit(n + 1, 0) {}

    void add(int i, int delta) {
        for (i++; i <= n; i += i & -i) {
            bit[i] += delta;
        }
    }

    long long sum(int i) {
        long long res = 0;
        for (; i > 0; i -= i & -i) {
            res += bit[i];
        }
        return res;
    }

    long long sum(int l, int r) {
        return sum(r) - sum(l);
    }
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;

    vector<int> a(n);
    Fenwick fen(n);
    SegmentWalk segwalk(n);
    Paint paint(n);

    for (int i = 0; i < n; i++) {
        cin >> a[i];
        fen.add(i, a[i]);
        segwalk.set(i, a[i]);
    }

    auto findSaturator = [&](int i) -> array<int, 2> {
        int l = i, r = i + 1;
        long long sum = a[i];
        while (l > 0 || r < n) {
            long long old_sum = sum;
            if (l > 0) {
                int p = segwalk.walk(0, l, sum, false);
                if (p == -1) {
                    sum += fen.sum(l);
                    l = 0;
                } else {
                    sum += fen.sum(p + 1, l);
                    l = p + 1;
                    if (sum >= a[p]) {
                        sum += a[p];
                        l = p;
                    }
                }
            }
            if (r < n) {
                int p = segwalk.walk(r, n, sum, true);
                if (p == -1) {
                    sum += fen.sum(r, n);
                    r = n;
                } else {
                    sum += fen.sum(r, p);
                    r = p;
                    if (sum >= a[p]) {
                        sum += a[p];
                        r = p + 1;
                    }
                }
            }
            if (sum == old_sum) break;
        }
        return {l, r};
    };

    int q;
    cin >> q;
    while (q--) {
        int type;
        cin >> type;
        if (type == 1) {
            int i, x;
            cin >> i >> x;
            i--;
            fen.add(i, -a[i] + x);
            a[i] = x;
            segwalk.set(i, x);
        }
        if (type == 2) {
            int l, r;
            cin >> l >> r;
            l--;

            // assumes l = 0, r = n;
            int res = 0;
            for (int i = 0; i < n; i++) {
                if (findSaturator(i) == array<int, 2>{0, n}) res++;
            }
            cout << res << '\n';
        }
    }
}

• Subtask 1: 0 / 5
• Subtask 2: 8 / 8
• Subtask 3: 0 / 12
• Subtask 4: 0 / 23
• Subtask 5: 0 / 35
• Subtask 6: 0 / 17