Submission #334825

#	Time	Username	Problem	Language	Result	Execution time	Memory
334825		juggernaut	Birthday gift (IZhO18_treearray)	C++14	56 / 100	153 ms	748 KiB

treearray

#include<bits/stdc++.h>
using namespace std;
int n,m,q,a[2005],up[2005][11],tin[2005],tout[2005],timer;
vector<int>g[2005];
void dfs(int v,int p){
    tin[v]=++timer;
    up[v][0]=p;
    for(int i=1;i<11;i++)up[v][i]=up[up[v][i-1]][i-1];
    for(int to:g[v])if(to!=p)dfs(to,v);
    tout[v]=++timer;
}
bool upper(int a,int b){
    return tin[a]<=tin[b]&&tout[a]>=tout[b];
}
int lca(int a,int b){
    if(upper(a,b))return a;
    if(upper(b,a))return b;
    for(int i=10;i>=0;i--)
        if(!upper(up[a][i],b))a=up[a][i];
    return up[a][0];
}
int main(){
    scanf("%d%d%d",&n,&m,&q);
    for(int i=1;i<n;i++){
        int x,y;
        scanf("%d%d",&x,&y);
        g[x].push_back(y);
        g[y].push_back(x);
    }
    dfs(1,1);
    for(int i=1;i<=m;i++)scanf("%d",&a[i]);
    while(q--){
        int type;
        scanf("%d",&type);
        if(type&1){
            int pos,val;
            scanf("%d%d",&pos,&val);
            a[pos]=val;
        }else{
            int l,r,v,al=-1,ar=-1;
            scanf("%d%d%d",&l,&r,&v);
            for(int i=l;i<r;i++){
                if(a[i]==v){
                    al=i;
                    ar=i;
                    break;
                }
                if(lca(a[i],a[i+1])==v){
                    al=i;
                    ar=i+1;
                    break;
                }
            }
            if(a[r]==v){
                al=r;
                ar=r;
            }
            printf("%d %d\n",al,ar);
        }
    }
}

Compilation message (stderr)

treearray.cpp: In function 'int main()':
treearray.cpp:23:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   23 |     scanf("%d%d%d",&n,&m,&q);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~
treearray.cpp:26:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   26 |         scanf("%d%d",&x,&y);
      |         ~~~~~^~~~~~~~~~~~~~
treearray.cpp:31:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   31 |     for(int i=1;i<=m;i++)scanf("%d",&a[i]);
      |                          ~~~~~^~~~~~~~~~~~
treearray.cpp:34:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   34 |         scanf("%d",&type);
      |         ~~~~~^~~~~~~~~~~~
treearray.cpp:37:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   37 |             scanf("%d%d",&pos,&val);
      |             ~~~~~^~~~~~~~~~~~~~~~~~
treearray.cpp:41:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   41 |             scanf("%d%d%d",&l,&r,&v);
      |             ~~~~~^~~~~~~~~~~~~~~~~~~

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