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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
#75435	#5307. Subgraph Isomorphism	team1377^#	WA	74ms	6540kb	C++14	2.8kb	2023-02-05 10:35:41	2023-02-05 10:35:42

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你现在查看的是测评时间为 2023-02-05 10:35:42 的历史记录

[2023-10-15 17:24:16]
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测评结果：WA
用时：45ms
内存：7100kb

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

[2023-02-05 10:35:42]
评测

测评结果：0
用时：74ms
内存：6540kb

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[2023-02-05 10:35:41]
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, int fa2 = -1)
{
    siz[x] = 1;
    vector<int> tmp;
    for (int i = 0; i < G[x].size(); ++i) {
        int v = G[x][i];
        if (v == fa || v == fa2) {
            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() == 2) {
                    int tmp = a;
                    a = b, b = c, c = d, d = tmp;
                }
                if (G[b].size() != 2 || G[d].size() != 2) {
                    puts("NO");
                } else {
                    if (hhash(a, b, d) == hhash(c, b, d)) {
                        puts("YES");
                    } else {
                        puts("NO");
                    }
                }
            }
        }
    }
    return 0;
}

源文件, 语言: C++14

詳細信息

Test #1:

score: 100

Accepted

time: 2ms

memory: 6264kb

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: 74ms

memory: 6540kb

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]