Submission #207430

#	Time	Username	Problem	Language	Result	Execution time	Memory
207430		mohamedsobhi777	Birthday gift (IZhO18_treearray)	C++14	56 / 100	4049 ms	20928 KiB

treearray

#include<bits/stdc++.h> 
 
using namespace std ;

const int N = 2e5 + 7 ; 

int n , t , m, q; 
vector<int> adj[N] ; 
vector<int> path; 
int st[N] , en[N] ; 
int a[N]; 
int col[N] ; 

void dfs(int x , int p)
{   
    st[x] = t++ ; 
    path.push_back(x);
    for(auto u : adj[x])
    {       
        if(u==p)
        continue;
        dfs(u , x) ; 
    }
    en[x] = t++; 
    path.push_back(x) ; 
}

bool inside(int L, int R , int l , int r)
{
    return (l>=L && l<=R && r>=L && r<=R);
}

int main() 
{
   /// freopen("in.in" , "r" , stdin) ; 
    cin>>n>>m>>q; 
    for(int i = 0 ; i < n-1 ; i++)
    {
        int a, b ; 
        cin>>a>>b ; 
        adj[a].push_back(b) ; 
        adj[b].push_back(a) ; 
    }
    dfs(1 , 1) ; 
    for(int i = 0 ; i<m ; i++)
    {
        cin>>a[i] ; 
    }
    while(q--)
    {
        int idx , A , B; 
        cin>>idx>>A>>B ; 

        if(idx==1)
        {
            a[A-1] = B; 
        }
        else
        {
            int C; 
            cin>>C ; 
            int l = st[C] , r = en[C] ;  
            int nodeA = -2 , nodeB = -2;

            int color = 0 ;          
            int ls = 0 , rs = 0 ;    
            memset(col , -1 , sizeof col);
            for(int i = l+1 ; i<= r-1 ; i++)
            {
                if(ls==rs)
                    color++ ;
                col[path[i]] = color ; 
                if( i==st[path[i]] ) 
                    ls++;
                else rs++;
            }
            if(a[A-1]==C)
            {
                nodeA = A-1 ; 
                nodeB = A-1 ; 
            }
            else 
            for(int i = A ; i<= B-1 ; i++)
            {
                if(col[a[i] ] != col[a[i-1]] && col[a[i]]!=-1 && col[a[i-1]]!=-1)
                {
                    nodeA = i-1 ; 
                    nodeB = i ;
                    break;
                }
                if(a[i]==C)
                {
                    nodeA = i ; 
                    nodeB = i ; 
                    break;
                }
            }


            cout<<nodeA+1<<" " <<nodeB+1<<"\n" ; 
        }
        
    }
    return 0 ;  
}

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 26 / 26
• Subtask 4: 0 / 44