oj.uz

답안 #928358

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
928358 2024-02-16T08:56:43 Z vjudge1 Amusement Park (CEOI19_amusementpark) C++17
100 / 100
 2009 ms 4692 KB 
// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #include <x86intrin.h>

#include <bits/stdc++.h>
#include <chrono>
#include <random>

// @author: Vlapos

namespace operators
{
    template <typename T1, typename T2>
    std::istream &operator>>(std::istream &in, std::pair<T1, T2> &x)
    {
        in >> x.first >> x.second;
        return in;
    }

    template <typename T1, typename T2>
    std::ostream &operator<<(std::ostream &out, std::pair<T1, T2> x)
    {
        out << x.first << " " << x.second;
        return out;
    }

    template <typename T1>
    std::istream &operator>>(std::istream &in, std::vector<T1> &x)
    {
        for (auto &i : x)
            in >> i;
        return in;
    }

    template <typename T1>
    std::ostream &operator<<(std::ostream &out, std::vector<T1> &x)
    {
        for (auto &i : x)
            out << i << " ";
        return out;
    }

    template <typename T1>
    std::ostream &operator<<(std::ostream &out, std::set<T1> &x)
    {
        for (auto &i : x)
            out << i << " ";
        return out;
    }
}

// name spaces
using namespace std;
using namespace operators;
// end of name spaces

// defines
#define ll long long
#define ull unsigned long long
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define pll pair<ll, ll>
#define f first
#define s second
#define uint unsigned int
#define all(vc) vc.begin(), vc.end()
// end of defines

// usefull stuff

void boost()
{
    ios_base ::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}

inline int getbit(int &x, int &bt) { return (x >> bt) & 1; }

const int dx4[4] = {-1, 0, 0, 1};
const int dy4[4] = {0, -1, 1, 0};
const int dx8[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
const int dy8[8] = {-1, -0, 1, -1, 1, -1, 0, 1};

const ll INF = (1e18) + 500;
const int BIG = (1e9) * 2 + 100;
const int MAXN = (1e5) + 5;
const int MOD7 = (1e9) + 7;
const int MOD9 = (1e9) + 9;
const uint MODFFT = 998244353;

#define int ll

vector<ll> fact;

void initfact(ll sz, ll mod)
{
    fact.resize(sz);
    fact[0] = 1;
    for (int i = 1; i < sz; i++)
    {
        fact[i] = (fact[i - 1] * i);
        fact[i] %= mod;
    }
}
ll binpow(ll val, ll deg, ll mod)
{
    if (!deg)
        return 1 % mod;
    if (deg & 1)
        return binpow(val, deg - 1, mod) * val % mod;
    ll res = binpow(val, deg >> 1, mod);
    return (res * res) % mod;
}
ll invert(ll n, int mod)
{
    return binpow(n, mod - 2, mod);
}
ll cnk(int n, int k, int mod)
{
    ll res = fact[n];
    ll div = fact[n - k] * fact[k];
    div %= mod;
    div = binpow(div, mod - 2, mod);
    return (res * div) % mod;
}

struct test
{
    vector<vector<int>> graph;
    vector<int> was;
    int n, m;

    bool dfs(int v)
    {
        was[v] = 1;
        for (int i = 0; i < n; ++i)
            if (graph[v][i] and was[i] != 2)
            {
                if (was[i] == 1 or !dfs(i))
                    return false;
            }
        was[v] = 2;
        return true;
    }

    void solve(int testcase)
    {
        boost();

        cin >> n >> m;

        was.resize(n);
        graph.resize(n, vector<int>(n));
        vector<pii> edges;

        for (int i = 0; i < m; ++i)
        {
            int v, tov;
            cin >> v >> tov;
            --v, --tov;
            edges.pb({v, tov});
            graph[v][tov] = 1;
        }

        int res = 0;

        int mxMask = (1 << n);

        vector<int> good(mxMask), dp(mxMask);
        dp[0] = 1;

        for (int mask = 0; mask < mxMask; ++mask)
        {
            good[mask] = 1;
            for (int i = 0; i < n; ++i)
                for (int j = 0; j < n; ++j)
                    if ((mask & (1 << i)) and (mask & (1 << j)) and (graph[i][j] or graph[j][i]))
                        good[mask] = 0;
        }

        for (int mask = 1; mask < mxMask; ++mask)
            for (int sub = mask; sub > 0; sub = (sub - 1) & mask)
                if (good[sub])
                {
                    // cout << mask << " " << sub << "!\n";
                    if (__popcount(sub) % 2)
                        dp[mask] = (dp[mask] + dp[mask ^ sub] + MODFFT) % MODFFT;
                    else
                        dp[mask] = (dp[mask] - dp[mask ^ sub] + MODFFT) % MODFFT;
                }
        // cout << dp << "!\n";

        cout << (((dp[mxMask - 1] * m) % MODFFT) * invert(2, MODFFT)) % MODFFT << "\n";
    }
};

main()
{
    boost();
    int q = 1;
    // cin >> q;
    for (int i = 0; i < q; i++)
    {
        test t;
        t.solve(i);
    }
    return 0;
}
//[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]//
//                                                                                    //
//                               Coded by Der_Vlἀpos                                  //
//                                                                                    //
//[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]//

Compilation message

amusementpark.cpp: In member function 'void test::solve(long long int)':
amusementpark.cpp:167:13: warning: unused variable 'res' [-Wunused-variable]
  167 |         int res = 0;
      |             ^~~
amusementpark.cpp: At global scope:
amusementpark.cpp:199:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  199 | main()
      | ^~~~

Subtask #1
7.0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct

Subtask #2
12.0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 0 ms 348 KB Output is correct
24 Correct 0 ms 348 KB Output is correct

Subtask #3
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 0 ms 348 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 0 ms 348 KB Output is correct
26 Correct 1 ms 348 KB Output is correct
27 Correct 0 ms 600 KB Output is correct
28 Correct 0 ms 344 KB Output is correct
29 Correct 0 ms 348 KB Output is correct
30 Correct 0 ms 348 KB Output is correct
31 Correct 0 ms 348 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 0 ms 348 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 0 ms 348 KB Output is correct
36 Correct 1 ms 348 KB Output is correct
37 Correct 0 ms 348 KB Output is correct
38 Correct 1 ms 348 KB Output is correct
39 Correct 1 ms 348 KB Output is correct
40 Correct 1 ms 348 KB Output is correct
41 Correct 1 ms 348 KB Output is correct
42 Correct 1 ms 348 KB Output is correct
43 Correct 1 ms 348 KB Output is correct
44 Correct 1 ms 452 KB Output is correct
45 Correct 1 ms 344 KB Output is correct
46 Correct 1 ms 348 KB Output is correct
47 Correct 0 ms 348 KB Output is correct
48 Correct 0 ms 348 KB Output is correct
49 Correct 1 ms 348 KB Output is correct
50 Correct 0 ms 348 KB Output is correct
51 Correct 1 ms 348 KB Output is correct
52 Correct 1 ms 360 KB Output is correct
53 Correct 1 ms 348 KB Output is correct
54 Correct 1 ms 348 KB Output is correct
55 Correct 1 ms 452 KB Output is correct
56 Correct 1 ms 348 KB Output is correct
57 Correct 1 ms 348 KB Output is correct
58 Correct 1 ms 344 KB Output is correct
59 Correct 1 ms 348 KB Output is correct
60 Correct 1 ms 348 KB Output is correct
61 Correct 1 ms 348 KB Output is correct
62 Correct 1 ms 604 KB Output is correct
63 Correct 1 ms 348 KB Output is correct
64 Correct 1 ms 348 KB Output is correct

Subtask #4
21.0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 0 ms 348 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 0 ms 348 KB Output is correct
26 Correct 1 ms 348 KB Output is correct
27 Correct 0 ms 600 KB Output is correct
28 Correct 0 ms 344 KB Output is correct
29 Correct 0 ms 348 KB Output is correct
30 Correct 0 ms 348 KB Output is correct
31 Correct 0 ms 348 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 0 ms 348 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 0 ms 348 KB Output is correct
36 Correct 1 ms 348 KB Output is correct
37 Correct 0 ms 348 KB Output is correct
38 Correct 1 ms 348 KB Output is correct
39 Correct 1 ms 348 KB Output is correct
40 Correct 1 ms 348 KB Output is correct
41 Correct 1 ms 348 KB Output is correct
42 Correct 1 ms 348 KB Output is correct
43 Correct 1 ms 348 KB Output is correct
44 Correct 1 ms 452 KB Output is correct
45 Correct 1 ms 344 KB Output is correct
46 Correct 1 ms 348 KB Output is correct
47 Correct 0 ms 348 KB Output is correct
48 Correct 0 ms 348 KB Output is correct
49 Correct 1 ms 348 KB Output is correct
50 Correct 0 ms 348 KB Output is correct
51 Correct 1 ms 348 KB Output is correct
52 Correct 1 ms 360 KB Output is correct
53 Correct 1 ms 348 KB Output is correct
54 Correct 1 ms 348 KB Output is correct
55 Correct 1 ms 452 KB Output is correct
56 Correct 1 ms 348 KB Output is correct
57 Correct 1 ms 348 KB Output is correct
58 Correct 1 ms 344 KB Output is correct
59 Correct 1 ms 348 KB Output is correct
60 Correct 1 ms 348 KB Output is correct
61 Correct 1 ms 348 KB Output is correct
62 Correct 1 ms 604 KB Output is correct
63 Correct 1 ms 348 KB Output is correct
64 Correct 1 ms 348 KB Output is correct
65 Correct 18 ms 708 KB Output is correct
66 Correct 19 ms 604 KB Output is correct
67 Correct 17 ms 604 KB Output is correct
68 Correct 17 ms 600 KB Output is correct
69 Correct 24 ms 612 KB Output is correct
70 Correct 19 ms 604 KB Output is correct
71 Correct 21 ms 600 KB Output is correct
72 Correct 20 ms 600 KB Output is correct
73 Correct 17 ms 600 KB Output is correct
74 Correct 18 ms 604 KB Output is correct
75 Correct 19 ms 732 KB Output is correct
76 Correct 18 ms 600 KB Output is correct
77 Correct 48 ms 856 KB Output is correct
78 Correct 44 ms 968 KB Output is correct
79 Correct 43 ms 1108 KB Output is correct
80 Correct 43 ms 860 KB Output is correct
81 Correct 43 ms 856 KB Output is correct
82 Correct 44 ms 860 KB Output is correct
83 Correct 38 ms 856 KB Output is correct
84 Correct 39 ms 984 KB Output is correct
85 Correct 62 ms 860 KB Output is correct
86 Correct 51 ms 856 KB Output is correct
87 Correct 51 ms 860 KB Output is correct
88 Correct 54 ms 860 KB Output is correct
89 Correct 44 ms 860 KB Output is correct
90 Correct 43 ms 972 KB Output is correct
91 Correct 47 ms 860 KB Output is correct
92 Correct 47 ms 972 KB Output is correct

Subtask #5
37.0 / 37.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 0 ms 348 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 0 ms 348 KB Output is correct
26 Correct 1 ms 348 KB Output is correct
27 Correct 0 ms 600 KB Output is correct
28 Correct 0 ms 344 KB Output is correct
29 Correct 0 ms 348 KB Output is correct
30 Correct 0 ms 348 KB Output is correct
31 Correct 0 ms 348 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 0 ms 348 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 0 ms 348 KB Output is correct
36 Correct 1 ms 348 KB Output is correct
37 Correct 0 ms 348 KB Output is correct
38 Correct 1 ms 348 KB Output is correct
39 Correct 1 ms 348 KB Output is correct
40 Correct 1 ms 348 KB Output is correct
41 Correct 1 ms 348 KB Output is correct
42 Correct 1 ms 348 KB Output is correct
43 Correct 1 ms 348 KB Output is correct
44 Correct 1 ms 452 KB Output is correct
45 Correct 1 ms 344 KB Output is correct
46 Correct 1 ms 348 KB Output is correct
47 Correct 0 ms 348 KB Output is correct
48 Correct 0 ms 348 KB Output is correct
49 Correct 1 ms 348 KB Output is correct
50 Correct 0 ms 348 KB Output is correct
51 Correct 1 ms 348 KB Output is correct
52 Correct 1 ms 360 KB Output is correct
53 Correct 1 ms 348 KB Output is correct
54 Correct 1 ms 348 KB Output is correct
55 Correct 1 ms 452 KB Output is correct
56 Correct 1 ms 348 KB Output is correct
57 Correct 1 ms 348 KB Output is correct
58 Correct 1 ms 344 KB Output is correct
59 Correct 1 ms 348 KB Output is correct
60 Correct 1 ms 348 KB Output is correct
61 Correct 1 ms 348 KB Output is correct
62 Correct 1 ms 604 KB Output is correct
63 Correct 1 ms 348 KB Output is correct
64 Correct 1 ms 348 KB Output is correct
65 Correct 18 ms 708 KB Output is correct
66 Correct 19 ms 604 KB Output is correct
67 Correct 17 ms 604 KB Output is correct
68 Correct 17 ms 600 KB Output is correct
69 Correct 24 ms 612 KB Output is correct
70 Correct 19 ms 604 KB Output is correct
71 Correct 21 ms 600 KB Output is correct
72 Correct 20 ms 600 KB Output is correct
73 Correct 17 ms 600 KB Output is correct
74 Correct 18 ms 604 KB Output is correct
75 Correct 19 ms 732 KB Output is correct
76 Correct 18 ms 600 KB Output is correct
77 Correct 48 ms 856 KB Output is correct
78 Correct 44 ms 968 KB Output is correct
79 Correct 43 ms 1108 KB Output is correct
80 Correct 43 ms 860 KB Output is correct
81 Correct 43 ms 856 KB Output is correct
82 Correct 44 ms 860 KB Output is correct
83 Correct 38 ms 856 KB Output is correct
84 Correct 39 ms 984 KB Output is correct
85 Correct 62 ms 860 KB Output is correct
86 Correct 51 ms 856 KB Output is correct
87 Correct 51 ms 860 KB Output is correct
88 Correct 54 ms 860 KB Output is correct
89 Correct 44 ms 860 KB Output is correct
90 Correct 43 ms 972 KB Output is correct
91 Correct 47 ms 860 KB Output is correct
92 Correct 47 ms 972 KB Output is correct
93 Correct 1107 ms 4556 KB Output is correct
94 Correct 1174 ms 4560 KB Output is correct
95 Correct 1207 ms 4560 KB Output is correct
96 Correct 954 ms 4564 KB Output is correct
97 Correct 854 ms 4560 KB Output is correct
98 Correct 960 ms 4560 KB Output is correct
99 Correct 139 ms 1368 KB Output is correct
100 Correct 114 ms 1372 KB Output is correct
101 Correct 110 ms 1624 KB Output is correct
102 Correct 104 ms 1368 KB Output is correct
103 Correct 690 ms 2504 KB Output is correct
104 Correct 460 ms 2648 KB Output is correct
105 Correct 382 ms 2504 KB Output is correct
106 Correct 305 ms 2396 KB Output is correct
107 Correct 2009 ms 4556 KB Output is correct
108 Correct 1002 ms 4596 KB Output is correct
109 Correct 851 ms 4560 KB Output is correct
110 Correct 708 ms 4556 KB Output is correct
111 Correct 100 ms 1484 KB Output is correct
112 Correct 96 ms 1372 KB Output is correct
113 Correct 97 ms 1484 KB Output is correct
114 Correct 185 ms 1480 KB Output is correct
115 Correct 192 ms 1476 KB Output is correct
116 Correct 167 ms 1372 KB Output is correct
117 Correct 183 ms 1372 KB Output is correct
118 Correct 133 ms 1484 KB Output is correct
119 Correct 121 ms 1484 KB Output is correct
120 Correct 120 ms 1624 KB Output is correct
121 Correct 129 ms 1484 KB Output is correct
122 Correct 294 ms 2512 KB Output is correct
123 Correct 272 ms 2396 KB Output is correct
124 Correct 256 ms 2508 KB Output is correct
125 Correct 250 ms 2396 KB Output is correct
126 Correct 246 ms 2560 KB Output is correct
127 Correct 245 ms 2396 KB Output is correct
128 Correct 239 ms 2516 KB Output is correct
129 Correct 226 ms 2512 KB Output is correct
130 Correct 229 ms 2520 KB Output is correct
131 Correct 555 ms 2396 KB Output is correct
132 Correct 438 ms 2512 KB Output is correct
133 Correct 439 ms 2520 KB Output is correct
134 Correct 441 ms 2548 KB Output is correct
135 Correct 362 ms 2512 KB Output is correct
136 Correct 331 ms 2508 KB Output is correct
137 Correct 367 ms 2512 KB Output is correct
138 Correct 332 ms 2504 KB Output is correct
139 Correct 292 ms 2396 KB Output is correct
140 Correct 321 ms 2504 KB Output is correct
141 Correct 321 ms 2508 KB Output is correct
142 Correct 645 ms 4564 KB Output is correct
143 Correct 628 ms 4688 KB Output is correct
144 Correct 621 ms 4564 KB Output is correct
145 Correct 657 ms 4564 KB Output is correct
146 Correct 583 ms 4440 KB Output is correct
147 Correct 565 ms 4572 KB Output is correct
148 Correct 692 ms 4564 KB Output is correct
149 Correct 637 ms 4568 KB Output is correct
150 Correct 649 ms 4692 KB Output is correct
151 Correct 740 ms 4560 KB Output is correct
152 Correct 746 ms 4576 KB Output is correct
153 Correct 973 ms 4564 KB Output is correct
154 Correct 1014 ms 4560 KB Output is correct
155 Correct 990 ms 4560 KB Output is correct
156 Correct 953 ms 4560 KB Output is correct
157 Correct 933 ms 4560 KB Output is correct
158 Correct 991 ms 4444 KB Output is correct
159 Correct 818 ms 4560 KB Output is correct
160 Correct 794 ms 4444 KB Output is correct
161 Correct 855 ms 4560 KB Output is correct
162 Correct 736 ms 4640 KB Output is correct
163 Correct 711 ms 4568 KB Output is correct
164 Correct 690 ms 4440 KB Output is correct
165 Correct 707 ms 4564 KB Output is correct
166 Correct 714 ms 4688 KB Output is correct
167 Correct 733 ms 4688 KB Output is correct