#866105 (C++17) No.2289 順列ソート

• 問題: No.2289 順列ソート
• ユーザー: rniya
• 提出日時: 2023-05-05 21:21:30
• 言語: C++17 (gcc 13.3.0 + boost 1.87.0)
• 結果: AC
• 実行時間: 14 ms / 2,000 ms
• コード長: 2,561 bytes
• コンパイル時間: 1,915 ms
• コンパイル使用メモリ: 197,840 KB
• 最終ジャッジ日時: 2025-02-12 17:22:37
• ジャッジサーバーID （参考情報）: judge3 / judge2

ファイルパターン	結果
sample	AC * 3
other	AC * 21

ソースコード

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
#include <bits/stdc++.h>
#ifdef LOCAL
#include <debug.hpp>
#else
#define debug(...) void(0)
#endif
struct UnionFind {
    UnionFind(int n) : n(n), num(n), data(n, -1) {}
    int find(int x) {
        assert(0 <= x && x < n);
        return data[x] < 0 ? x : data[x] = find(data[x]);
    }
    bool merge(int x, int y) {
        assert(0 <= x && x < n);
        assert(0 <= y && y < n);
        if ((x = find(x)) == (y = find(y))) return false;
        if (-data[x] < -data[y]) std::swap(x, y);
        data[x] += data[y];
        data[y] = x;
        num--;
        return true;
    }
    bool same(int x, int y) {
        assert(0 <= x && x < n);
        assert(0 <= y && y < n);
        return find(x) == find(y);
    }
    int size(int x) {
        assert(0 <= x && x < n);
        return -data[find(x)];
    }
    int count() const { return num; }
    std::vector<std::vector<int>> groups() {
        std::vector<std::vector<int>> res(n);
        for (int i = 0; i < n; i++) res[find(i)].emplace_back(i);
        res.erase(std::remove_if(res.begin(), res.end(), [&](const std::vector<int>& v) { return v.empty(); }));
        return res;
    }
    int operator[](int x) { return find(x); }
private:
    int n, num;
    // root node : -1 * component size
    // otherwise : parent
    std::vector<int> data;
};
using namespace std;
typedef long long ll;
#define all(x) begin(x), end(x)
constexpr int INF = (1 << 30) - 1;
constexpr long long IINF = (1LL << 60) - 1;
constexpr int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
template <class T> istream& operator>>(istream& is, vector<T>& v) {
    for (auto& x : v) is >> x;
    return is;
}
template <class T> ostream& operator<<(ostream& os, const vector<T>& v) {
    auto sep = "";
    for (const auto& x : v) os << exchange(sep, " ") << x;
    return os;
}
template <class T, class U = T> bool chmin(T& x, U&& y) { return y < x and (x = forward<U>(y), true); }
template <class T, class U = T> bool chmax(T& x, U&& y) { return x < y and (x = forward<U>(y), true); }
template <class T> void mkuni(vector<T>& v) {
    sort(begin(v), end(v));
    v.erase(unique(begin(v), end(v)), end(v));
}
template <class T> int lwb(const vector<T>& v, const T& x) { return lower_bound(begin(v), end(v), x) - begin(v); }
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N;
    cin >> N;
    UnionFind UF(N);
    for (int i = 0; i < N; i++) {
        int P;
        cin >> P;
        UF.merge(i, --P);
    }
    int ans = N - UF.count();
    cout << ans << '\n';
    return 0;
}
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX