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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
#75445	#5307. Subgraph Isomorphism	team1377^#	WA	73ms	6608kb	C++14	2.5kb	2023-02-05 10:43:38	2023-02-05 10:43:38

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你现在查看的是测评时间为 2023-02-05 10:43:38 的历史记录

[2023-10-15 17:24:16]
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测评结果：WA
用时：49ms
内存：6600kb

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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 10:43:38]
评测

测评结果：0
用时：73ms
内存：6608kb

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[2023-02-05 10:43:38]
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 {
            S.clear();
            cyc.clear();
            dfs(1);
            if (!cyc.size()) {
                puts("NO");
            } else {
                vector<int> hs;
                for (int i = 0; i < cyc.size(); ++i) {
                    hs.push_back(hhash(cyc[i], cyc[(i - 1 + cyc.size()) % cyc.size()], cyc[(i + 1) % cyc.size()]));
                }
                int flag = 1;
                for (int i = 2; i < cyc.size(); ++i) {
                    flag &= hs[i] == hs[i - 2];
                }
                if (flag) {
                    puts("YES");
                } else {
                    puts("NO");
                }
            }
        }
    }
    return 0;
}

源文件, 语言: C++14

详细

Test #1:

score: 100

Accepted

time: 4ms

memory: 6608kb

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: 73ms

memory: 6340kb

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
YES
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 NO, found YES [374th token]