Submission #57810

#	Time	Username	Problem	Language	Result	Execution time	Memory
57810		red1108	트리 (KOI16_tree)	C++17	55 / 100	2067 ms	23724 KiB

tree

#include <stdio.h>
#include <vector>
using namespace std;
int n,q;
vector<int> tree[200010];
int seg[800010],par[200010],cnt=0,si=1,color[800010],ccnt=1;
pair<int,int> range[200010];
bool cut[200010];
void dfs(int x)
{
    range[x].first=++cnt;
    for(auto i:tree[x])
        dfs(i);
    range[x].second=cnt;
}
void rename(int x,int newc)
{
    color[x]=newc;
    for(auto i:tree[x])
    {
        if(!cut[i]) rename(i,newc);
    }
}
void gang(int x, int k)
{
    x=x+si-1;
    int delta=k-seg[x];
    while(x)
    {
        seg[x]+=delta;
        x/=2;
    }
}
int getsize(int x, int l, int r, int s, int e)
{
    if(l>r||e<l||r<s)
        return 0;
    if(s<=l&&r<=e)
        return seg[x];
    return getsize(x*2,l,(l+r)/2,s,e)+getsize(x*2+1,(l+r)/2+1,r,s,e);
}
int main()
{
    int i,a,b,c,flag;
    scanf("%d %d", &n, &q);
    while(si<n)
        si*=2;
    for(i=2; i<=n; i++)
    {
        scanf("%d", &a);
        tree[a].push_back(i);
    }
    for(i=1;i<=n;i++)
        color[i]=1;
    par[1]=1;
    dfs(1);
    for(i=1;i<=n;i++)
    {
        gang(i,1);
    }
    for(i=1;i<=q;i++)
    {
        scanf("%d %d %d", &a, &b, &c);
        flag=0;
        if(color[a]==color[b])
        {
            printf("YES\n");
            flag=1;
        }
        else
            printf("NO\n");
        if(c==0)
            continue;
        if(!flag)
            a=b;
        if(cut[a]==1)
            continue;
        cut[a]=1;
        int sip, sia;
        sia=getsize(1,1,si,range[a].first+1,range[a].second)+1;
        gang(range[a].first,(-1)*sia+1);
        sip=getsize(1,1,si,range[par[color[a]]].first+1,range[par[color[a]]].second)+1;
        if(sip<=sia)
        {
            par[ccnt+1]=par[color[a]];
            int tmp=color[a];
            rename(par[color[a]],++ccnt);
            par[tmp]=a;
        }
        else
        {
            rename(a,++ccnt);
            par[ccnt]=a;
        }
    }
}

Compilation message (stderr)

tree.cpp: In function 'int main()':
tree.cpp:45:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &q);
     ~~~~~^~~~~~~~~~~~~~~~~
tree.cpp:50:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &a);
         ~~~~~^~~~~~~~~~
tree.cpp:63:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d %d", &a, &b, &c);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 13 / 13
• Subtask 3: 14 / 14
• Subtask 4: 19 / 19
• Subtask 5: 0 / 45