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ID	Problem	Submitter	Result	Time	Memory	Language	File size	Submit time	Judge time
#108157	#5307. Subgraph Isomorphism	why	WA	7ms	2280kb	C++14	2.2kb	2023-05-23 18:47:46	2023-05-23 18:47:48

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你现在查看的是测评时间为 2023-05-23 18:47:48 的历史记录

[2023-10-15 17:25:49]
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测评结果：WA
用时：9ms
内存：3408kb

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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.

[2023-05-23 18:47:48]
评测

测评结果：0
用时：7ms
内存：2280kb

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[2023-05-23 18:47:46]
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answer

#include<stdio.h>
#include<algorithm>
#include<math.h>
#include<string.h>
#include<queue>
#include<stack>
#include<vector>
#include<map>
#include<set>
#include<time.h>
#include<stdlib.h>
using namespace std;

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int,int> pii;
const int N=1e5+86;

int T,n,m;
struct edge{int to,nxt;}e[N<<1];
int head[N],tot;
void add(int u,int v){e[++tot]={v,head[u]},head[u]=tot;}

int rt,nxt[N],st[N],top;
bool vis[N];
bool ring(int u,int fa)
{
    if(vis[u])
    {
        rt=u;
        int now=u;
        while(st[top]!=u) nxt[st[top]]=now,now=st[top],top--;
        nxt[u]=now;
        top--;
        return true;
    }
    st[++top]=u;
    vis[u]=true;
    for(int i=head[u];i;i=e[i].nxt)
    {
        int v=e[i].to;
        if(v==fa) continue;
        if(ring(v,u)) return true;
    }
    vis[u]=false;
    top--;
    return false;
}
ull rep[N];
int siz[N];
ull hash_tree(int u,int fa)
{
    ull h=1;
    siz[u]=1;
    for(int i=head[u];i;i=e[i].nxt)
    {
        int v=e[i].to;
        if(v==fa||nxt[v]) continue;
        h+=hash_tree(v,u)*siz[v];
        siz[u]+=siz[v];
    }
    return h;
}
bool check()
{
    ull h[2]={hash_tree(rt,0),hash_tree(nxt[rt],0)};
    for(int f=0,now=nxt[nxt[rt]];now!=rt;now=nxt[now],f=!f)
        if(hash_tree(now,0)!=h[f]) return false;
    return true;
}

template<typename T>
inline void read(T &x)
{
    T k=1;char ch=getchar();x=0;
    while(ch<'0'||ch>'9'){if(ch=='-') k=-1;ch=getchar();}
    while(ch>='0'&&ch<='9')x=(x<<1)+(x<<3)+(ch^48),ch=getchar();
    x*=k;
}

signed main()
{
    srand(time(NULL));
    read(T);
    for(int i=1;i<=1e5;i++) rep[i]=((ull)rand()<<30)+((ull)rand<<15)+rand();
    while(T--)
    {
        read(n),read(m);
        memset(head+1,0,n<<2);
        memset(nxt+1,0,n<<2);
        memset(vis+1,0,n);
        tot=rt=top=0;
        for(int i=1,u,v;i<=m;i++)
            read(u),read(v),add(u,v),add(v,u);
        if(m>n)
        {
            puts("NO");
            continue;
        }
        if(m==n-1)
        {
            puts("YES");
            continue;
        }
        ring(1,0);
        if(check()) puts("YES");
        else puts("NO");
    }
    return 0;
}

Source code, Language: C++14

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100

Accepted

time: 0ms

memory: 2172kb

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: 7ms

memory: 2280kb

input:

output:

YES
YES
YES
YES
YES
YES
YES
NO
NO
YES
YES
YES
NO
NO
NO
NO
NO
YES
YES
NO
NO
NO
YES
NO
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
NO
NO
NO
YES
NO
NO
NO
NO
NO
YES
YES
NO
YES
YES
NO
YES
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
N...

result:

wrong answer expected NO, found YES [6th token]