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ID	题目	提交者	结果	用时	内存	语言	文件大小	提交时间	测评时间
#630574	#5307. Subgraph Isomorphism	333zhan	WA	55ms	3860kb	C++20	2.5kb	2024-10-11 19:19:11	2024-10-11 19:19:11

Judging History

你现在查看的是最新测评结果

[2024-10-11 19:19:11]
评测

测评结果：WA
用时：55ms
内存：3860kb

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[2024-10-11 19:19:11]
提交

answer

#include <bits/stdc++.h>
#define int long long

using namespace std;

using u64 = unsigned long long;

mt19937 rng (time (0));

u64 mask = rng ();

u64 shift (u64 x) {
    x ^= mask;
    x ^= x << 13;
    x ^= x >> 7;
    x ^= x << 17;
    x ^= mask;
    return x;
} 

void solve () {
    int n, m;
    cin >> n >> m;

    vector <vector <int>> e (n);
    for (int i = 0; i < m; i ++) {
        int x, y;
        cin >> x >> y;
        x --; y --;
        e[x].push_back (y);
        e[y].push_back (x);
    }

    if (m > n) {
        cout << "NO\n";
        return;
    }
    if (m < n) {
        cout << "YES\n";
        return;
    }

    vector <int> pre (n, -1);
    vector <int> path;
    vector <int> dfn (n);
    int ts = 0;

    auto dfs = [&] (auto &&self, int x, int fa) -> void {
        dfn[x] = ++ ts;
        for (auto y : e[x]) {
            if (y == fa) {
                continue;
            }
            if (! dfn[y]) {
                pre[y] = x;
                self (self, y, x);
            } else {
                if (dfn[y] < dfn[x]) {
                    continue;
                }
                int t = y;
                path.push_back (t);
                while (t != x) {
                    path.push_back (t);
                    t = pre[t];
                }
            }
        }
    };
    dfs (dfs, 0, -1);

    vector <int> ok (n);
    for (auto x : path) {
        ok[x] = true;
    }

    vector <u64> ans;
    vector <u64> hash (n);
    auto dfs2 = [&] (auto &&self, int x, int fa) -> void {
        hash[x] = 1;
        for (auto y : e[x]) {
            if (y == fa) {
                continue;
            }
            if (ok[y]) {
                continue;
            }
            self (self, y, x);
            hash[x] += shift (hash[y]);
        }
    };

    for (auto x : path) {
        dfs2 (dfs2, x, -1);
        ans.push_back (hash[x]);
    }

    if (count (ans.begin (), ans.end (), ans[0]) == path.size ()) {
        cout << "YES\n";
        return;
    }
    
    if (path.size () % 2 == 1) {
        cout << "NO\n";
        return;
    }

    for (int i = 2; i < ans.size (); i ++) {
        if (ans[i] != ans[i - 2]) {
            cout << "NO\n";
            return;
        }
    }
    cout << "YES\n";
}

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

    int T = 1;
    cin >> T;

    while (T --) {
        solve ();
    }

    return 0;
}

源文件, 语言: C++20

详细

Test #1:

score: 100

Accepted

time: 0ms

memory: 3660kb

input:

output:

YES
YES
NO
YES

result:

ok 4 token(s): yes count is 3, no count is 1

Test #2:

score: -100

Wrong Answer

time: 55ms

memory: 3860kb

input:

output:

YES
YES
YES
YES
YES
NO
NO
NO
NO
YES
YES
NO
YES
NO
NO
NO
NO
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
YES
YES
NO
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
YES
NO
NO
NO
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO...

result:

wrong answer expected YES, found NO [7th token]