QOJ.ac

QOJ

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
#75429	#5307. Subgraph Isomorphism	team1377^#	WA	50ms	6736kb	C++14	2.9kb	2023-02-05 10:25:50	2023-02-05 10:25:52

Judging History

你现在查看的是测评时间为 2023-02-05 10:25:52 的历史记录

[2023-10-15 17:24:15]
管理员手动重测本题所有提交记录

测评结果：WA
用时：50ms
内存：6596kb

查看

[2023-08-10 23:21:45]
System Update: QOJ starts to keep a history of the judgings of all the submissions.

[2023-02-05 10:25:52]
评测

测评结果：0
用时：50ms
内存：6736kb

查看

[2023-02-05 10:25:50]
提交

answer

#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 5;

vector<int> G[N];
vector<int> S, cyc;
int inS[N];

void dfs(int x, int fa = -1)
{
    S.push_back(x);
    inS[x] = 1;
    for (int i = 0; i < G[x].size(); ++i) {
        int v = G[x][i];
        if (v == fa) {
            continue;
        }
        if (inS[v]) {
            int p;
            do {
                p = S.back();
                S.pop_back();
                cyc.push_back(p);
            } while (p != v);
            return;
        }
        dfs(v, x);
        if (cyc.size()) {
            return;
        }
    }
    S.pop_back();
    inS[x] = 0;
    return;
}

int base[N], siz[N];

int hhash(int x, int fa = -1)
{
    siz[x] = 1;
    vector<int> tmp;
    for (int i = 0; i < G[x].size(); ++i) {
        int v = G[x][i];
        if (v == fa) {
            continue;
        }
        tmp.push_back(hhash(v, x));
        siz[x] += siz[v];
    }
    sort(tmp.begin(), tmp.end());
    int val = siz[x];
    for (int i = 0; i < tmp.size(); ++i) {
        val = (1ll * val * base[i] + tmp[i]) % 998244353;
    }
    return val;
}

signed main()
{
    mt19937 rnd;
    for (int i = 0; i < N; ++i) {
        base[i] = rnd() % 998244353;
    }
    int T;
    scanf("%d", &T);
    while (T--) {
        int n, m;
        scanf("%d%d", &n, &m);
        for (int i = 1; i <= n; ++i) {
            G[i].clear();
            inS[i] = 0;
        }
        for (int i = 1; i <= m; ++i) {
            int x, y;
            scanf("%d%d", &x, &y);
            G[x].push_back(y);
            G[y].push_back(x);
        }
        if (m == n - 1) {
            puts("YES");
        } else if (m != n) {
            puts("NO");
        } else {
            int flag = 1;
            for (int i = 1; i <= n; ++i) {
                if (G[i].size() != 2) {
                    flag = 0;
                    break;
                }
            }
            if (flag) {
                puts("YES");
                continue;
            }
            S.clear();
            cyc.clear();
            dfs(1);
            if (cyc.size() != 4) {
                puts("NO");
            } else {
                int a = cyc[0], b = cyc[1], c = cyc[2], d = cyc[3];
                if (G[a].size() != 3) {
                    int tmp = a;
                    a = b, b = c, c = d, d = tmp;
                }
                if (G[a].size() != 3 || G[b].size() != 2 || G[c].size() != 3 || G[d].size() != 2) {
                    puts("NO");
                } else {
                    int r1 = G[a][0] ^ G[a][1] ^ G[a][2] ^ b ^ d, r2 = G[c][0] ^ G[c][1] ^ G[c][2] ^ b ^ d;
                    if (hhash(r1, a) == hhash(r2, c)) {
                        puts("YES");
                    } else {
                        puts("NO");
                    }
                }
            }
        }
    }
    return 0;
}

源文件, 语言: C++14

詳細信息

Test #1:

score: 100

Accepted

time: 4ms

memory: 6648kb

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: 50ms

memory: 6736kb

input:

output:

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

result:

wrong answer expected YES, found NO [60th token]