Submission #57805

#	Time	Username	Problem	Language	Result	Execution time	Memory
57805		red1108	트리 (KOI16_tree)	C++17	0 / 100	10 ms	5112 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[200010],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;
        gang(range[a].first,(-1)*getsize(1,1,si,range[a].first+1,range[a].second));
        int sip, sia;
        sip=getsize(1,1,si,range[par[color[a]]].first+1,range[par[color[a]]].second)+1;
        sia=getsize(1,1,si,range[a].first+1,range[a].second)+1;
        if(sip<=sia) {par[ccnt]=par[color[a]];rename(par[color[a]],++ccnt);}
        else {rename(a,++ccnt);par[ccnt]=a;}
    }
}

Compilation message (stderr)

tree.cpp: In function 'int main()':
tree.cpp:42:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &q);
     ~~~~~^~~~~~~~~~~~~~~~~
tree.cpp:46:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &a);
         ~~~~~^~~~~~~~~~
tree.cpp:55:14: 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: 0 / 9
• Subtask 2: 0 / 13
• Subtask 3: 0 / 14
• Subtask 4: 0 / 19
• Subtask 5: 0 / 45