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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
#490650#6559. A Tree and Two EdgesSmallAoPigBigPiPig#TL 1243ms1227392kbC++172.3kb2024-07-25 16:00:242024-07-25 16:00:24

Judging History

你现在查看的是最新测评结果

  • [2024-07-25 16:00:24]
  • 评测
  • 测评结果:TL
  • 用时:1243ms
  • 内存:1227392kb
  • [2024-07-25 16:00:24]
  • 提交

answer

#include<bits/stdc++.h>
const int MAXN = 50011;
typedef std::pair<int,int> pii;
typedef std::bitset<MAXN> bits;
bits f[4][MAXN];
struct DSU
{
    int fa[MAXN];
    void init(int n)
    {
        for(int i=1;i<=n;++i)fa[i]=i;
    }
    int find(int x)
    {
        if(fa[x]==x)return x;
        return fa[x]=find(fa[x]);
    }
    bool uni(int x,int y)
    {
        x=find(x),y=find(y);
        if(x==y)return 0;
        fa[x]=y;
        return 1;
    }
}dsu;
std::vector<int>g[MAXN];
pii e[2];
void dfs(int k,int u,int pre)
{
    f[k][u]=f[k][pre];
    f[k][u].set(u);
    for(auto v:g[u])
        if(v!=pre)
        {
            dfs(k,v,u);
        }
}
int main()
{
    int n,q;
    scanf("%d%d",&n,&q);
    dsu.init(n);
    int c=0;
    for(int i=1;i<=n+1;++i)
    {
        int u,v;
        scanf("%d%d",&u,&v);
        if(dsu.uni(u,v))g[u].emplace_back(v),g[v].emplace_back(u);
        else e[c++]=pii(u,v);
    }
    for(int i=0;i<2;++i)
    {
        dfs(i<<1,e[i].first,0);
        dfs(i<<1|1,e[i].second,0);
    }
    while(q--)
    {
        int x,y;
        scanf("%d%d",&x,&y);
        int ans=1;
        for(int i=0;i<2;++i)
        {
            int a=e[i].first,b=e[i].second;
            auto &fa=f[i<<1],&fb=f[i<<1|1];
            if(!(fa[x]&fb[y]).any())++ans;
            if(!(fb[x]&fa[y]).any())++ans;
        }
        // x->(a,b) -> (c,d) -> y
        for(int i=0;i<2;++i)
        {
            int a=e[i].first,b=e[i].second;
            int c=e[i^1].first,d=e[i^1].second;
            auto &fa=f[i<<1],&fb=f[i<<1|1];
            auto &fc=f[(!i)<<1],&fd=f[(!i)<<1|1];
            //printf("consider (%d,%d) (%d,%d) (%d,,,)\n",a,b,c,d,fa[x].count());
            if(!(fa[x]&fb[c]).any()&&!(fa[x]&fd[y]).any()&&!(fb[c]&fd[y]).any())++ans;
            //printf("(%d,%d,%d)\n",(fb[x]&fa[c]).any(),(fb[x]&fd[y]).any(),(fa[c]&fd[y]).any());
            if(!(fb[x]&fa[c]).any()&&!(fb[x]&fd[y]).any()&&!(fa[c]&fd[y]).any())++ans;
            std::swap(fc,fd),std::swap(c,d);
            if(!(fa[x]&fb[c]).any()&&!(fa[x]&fd[y]).any()&&!(fb[c]&fd[y]).any())++ans;
            if(!(fb[x]&fa[c]).any()&&!(fb[x]&fd[y]).any()&&!(fa[c]&fd[y]).any())++ans;
            std::swap(fc,fd);
        }
        printf("%d\n",ans);
    }
    return 0;
}

詳細信息

Test #1:

score: 100
Accepted
time: 1243ms
memory: 1227392kb

input:

4 6
1 2
1 3
1 4
2 3
2 4
1 2
1 3
1 4
2 3
2 4
3 4

output:

3
3
3
3
3
4

result:

ok 6 lines

Test #2:

score: 0
Accepted
time: 820ms
memory: 1227200kb

input:

6 4
1 2
1 3
1 6
2 3
3 4
3 5
4 5
1 2
1 3
1 4
1 6

output:

2
2
4
1

result:

ok 4 lines

Test #3:

score: -100
Time Limit Exceeded

input:

50000 50000
11561 23122
14261 28523
24407 48814
17947 35894
14803 29607
19557 39115
12415 24830
9583 19167
18397 36794
439 878
18040 36080
17150 34300
7922 15845
18938 37877
18625 37250
6459 12919
9818 19636
3579 7158
21323 42646
23882 47764
13603 27207
8353 16707
15907 31814
20935 41871
11686 23372...

output:


result: