Submission #885368

#	Time	Username	Problem	Language	Result	Execution time	Memory
885368		Koyote	Fortune Telling 2 (JOI14_fortune_telling2)	C++11	100 / 100	317 ms	70816 KiB

fortune_telling2

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

#define TASK "flip"
 
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()

// Segment Tree (iterative)
template<class S, S (*op)(S, S), S (*e)()> struct segtree {
  private:
    int _n, _size, _log;
    vector<S> d;
    void updateS(int k) { d[k] = op(d[k << 1], d[k << 1 | 1]); }
    constexpr bool ineq(int x, int y, int z) const { return x <= y && y < z; }
  public:
    segtree() : segtree(0) {}
    explicit segtree(int __n) : segtree(vector<S>(__n, e())) {}
    explicit segtree(const vector<S> &v) : _n((int)v.size()) {
        _log = 31 - __builtin_clz(_n) + ((_n & -_n) != _n), _size = 1 << _log;
        d = vector<S>(_size << 1, e());
        for (int i = 0; i < _n; ++i) d[_size + i] = v[i];
        for (int i = _size - 1; i > 0; --i) updateS(i);
    }

    S query(int l, int r) { // [l, r)
        assert(ineq(0, l, r + 1) && ineq(l, r, _n + 1));
        S sml = e(), smr = e();
        for (l += _size, r += _size; l < r; l >>= 1, r >>= 1) {
            if (l & 1) sml = op(sml, d[l++]);
            if (r & 1) smr = op(d[--r], smr);
        }
        return op(sml, smr);
    }
};

int op(int x, int y) { return max(x, y); }
int e() { return 0; }
// End of Segment Tree (iterative)

// Merge Sort Tree
template<class T> struct merge_sort_tree {
    int _l, _r, _m;
    vector<T> v;
    merge_sort_tree *lt, *rt;
    merge_sort_tree(int l, int r, const vector<T> &e) : _l(l), _r(r), _m((l + r) >> 1) {
        v.resize(r - l + 1), v[0] = e[l];
        if (l == r) lt = rt = nullptr;
        else {
            lt = new merge_sort_tree(_l, _m, e);
            rt = new merge_sort_tree(_m + 1, _r, e);
            vector<T> v1 = lt->v, v2 = rt->v;
            v.resize(v1.size() + v2.size());
            merge(all(v1), all(v2), v.begin());
        }
    }
    int count(int l, int r, T a, T b) {
        if (a > b) return 0;
        if (l > _r || r < _l) return 0;
        if (_l >= l && _r <= r) return upper_bound(all(v), b) - lower_bound(all(v), a);
        return lt->count(l, r, a, b) + rt->count(l, r, a, b);
    }
};
// End of Merge Sort Tree
 
const int N = 2e5 + 7, N2 = 6e5 + 2, LG = 20;
int n, k, a[N], b[N], t[N], t_idx[N2], max_t_idx[LG][N2];
 
constexpr int lg2(const int x) { return 31 - __builtin_clz(x); }
 
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    if (fopen(TASK ".inp", "r")) {
        freopen(TASK ".inp", "r", stdin);
        freopen(TASK ".out", "w", stdout);
    }
    cin >> n >> k;
    for (int i = 1; i <= n; i++) cin >> a[i] >> b[i];
    for (int i = 1; i <= k; i++) cin >> t[i];
 
    basic_string<int> cmpr; cmpr.reserve(2 * n + k + 1), cmpr += 0;
    for (int i = 1; i <= n; i++) cmpr += a[i], cmpr += b[i];
    for (int i = 1; i <= k; i++) cmpr += t[i];
    sort(all(cmpr)), cmpr.erase(unique(all(cmpr)), cmpr.end());

    auto search = [&](const int v) -> int { return lower_bound(all(cmpr), v) - cmpr.begin(); };
    for (int i = 1; i <= n; i++) a[i] = search(a[i]), b[i] = search(b[i]);
    for (int i = 1; i <= k; i++) t[i] = search(t[i]), t_idx[t[i]] = i;
 
    // Sparse table
    // for (int i = 1; i <= sz(cmpr); i++) max_t_idx[0][i] = t_idx[i];
    // for (int j = 1; j < LG; j++)
    //     for (int i = 1; i + (1 << j) - 1 <= sz(cmpr); i++)
    //         max_t_idx[j][i] = max(max_t_idx[j - 1][i], max_t_idx[j - 1][i + (1 << (j - 1))]);
    
    // auto query_max_t_idx = [&](int l, int r) -> int {
    //     int len = lg2(r - l + 1);
    //     return max(max_t_idx[len][l], max_t_idx[len][r - (1 << len) + 1]);
    // };
    // End of Sparse table


    // Segment Tree (iterative)
    segtree<int, op, e> stree(vector<int>(t_idx, t_idx + sz(cmpr) + 1));
    auto query_max_t_idx = [&](int l, int r) -> int { return stree.query(l, r + 1); };
    // End of Segment Tree (iterative)

    // Merge Sort Tree
    merge_sort_tree<int> mst(0, k + 1, vector<int>(t, t + k + 1));

    // Number of i that (l <= i <= r) and (x <= a[i] <= y)
    auto cnt_on_range = [&](int l, int r, int x, int y) -> int {
        return mst.count(l, r, x, y);
    };
    // End of Merge Sort Tree
 
    basic_string<int> ans; ans.reserve(n);
    for (int i = 1; i <= n; i++) {
        if (a[i] == b[i]) { ans += cmpr[a[i]]; continue; }
        bool swapped = (a[i] > b[i] ? (swap(a[i], b[i]), true) : false);
        int last_pos = query_max_t_idx(a[i], b[i] - 1);
        int cnt_flipped = cnt_on_range(last_pos + 1, k, b[i], sz(cmpr));
 
        if (last_pos != 0 || swapped) swap(a[i], b[i]);
        ans += cmpr[~cnt_flipped & 1 ? a[i] : b[i]];
    }
    // for (int i : ans) cout << i << ' ';
    cout << accumulate(ans.begin(), ans.end(), 0LL) << '\n';
}

Compilation message (stderr)

fortune_telling2.cpp: In function 'int main()':
fortune_telling2.cpp:74:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |         freopen(TASK ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
fortune_telling2.cpp:75:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |         freopen(TASK ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 31 / 31
• Subtask 3: 65 / 65