Submission #542384

#	Time	Username	Problem	Language	Result	Execution time	Memory
542384		krit3379	Birthday gift (IZhO18_treearray)	C++17	100 / 100	1107 ms	77592 KiB

treearray

#include<bits/stdc++.h>
using namespace std;
#define N 200005
 
int dep[N],bp[20][N],val[N];
vector<int> g[N];
set<int> s[N],ss[N];
 
void dfs(int s,int f){
    dep[s]=dep[f]+1;
    bp[0][s]=f;
    for(auto x:g[s])if(x!=f)dfs(x,s);
}
 
int lca(int a,int b){
    if(dep[a]>dep[b])swap(a,b);
    int i,dif=dep[b]-dep[a];
    for(i=0;i<20;i++)if(dif&(1<<i))b=bp[i][b];
    if(a==b)return a;
    for(i=19;i>=0;i--)if(bp[i][a]!=bp[i][b]){
        a=bp[i][a];
        b=bp[i][b];
    }
    return bp[0][a];
}
 
int main(){
    int n,m,q,i,j,a,b,op,pos,v,l,r;
    scanf("%d %d %d",&n,&m,&q);
    for(i=1;i<n;i++){
        scanf("%d %d",&a,&b);
        g[a].push_back(b);
        g[b].push_back(a);
    }
    for(i=1;i<=m;i++)scanf("%d",&val[i]),s[val[i]].insert(i);
    dfs(1,1);
    for(i=1;i<20;i++)for(j=1;j<=n;j++)bp[i][j]=bp[i-1][bp[i-1][j]];
    for(i=1;i<m;i++)ss[lca(val[i],val[i+1])].insert(i);
    while(q--){
        scanf("%d",&op);
        if(op==1){
            scanf("%d %d",&pos,&v);
            s[val[pos]].erase(pos);
            s[v].insert(pos);
            if(pos>1){
                ss[lca(val[pos],val[pos-1])].erase(pos-1);
                ss[lca(v,val[pos-1])].insert(pos-1);
            }
            if(pos<m){
                ss[lca(val[pos],val[pos+1])].erase(pos);
                ss[lca(v,val[pos+1])].insert(pos);
            }
            val[pos]=v;
        }
        else{
            scanf("%d %d %d",&l,&r,&v);
            auto it1=s[v].lower_bound(l),it2=ss[v].lower_bound(l);
            if(it1!=s[v].end()&&*it1<=r)printf("%d %d\n",*it1,*it1);
            else if(it2!=ss[v].end()&&*it2<r)printf("%d %d\n",*it2,*it2+1);
            else printf("-1 -1\n");
        }
    }
    return 0;
}

Compilation message (stderr)

treearray.cpp: In function 'int main()':
treearray.cpp:29:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |     scanf("%d %d %d",&n,&m,&q);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~
treearray.cpp:31:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |         scanf("%d %d",&a,&b);
      |         ~~~~~^~~~~~~~~~~~~~~
treearray.cpp:35:27: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |     for(i=1;i<=m;i++)scanf("%d",&val[i]),s[val[i]].insert(i);
      |                      ~~~~~^~~~~~~~~~~~~~
treearray.cpp:40:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |         scanf("%d",&op);
      |         ~~~~~^~~~~~~~~~
treearray.cpp:42:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |             scanf("%d %d",&pos,&v);
      |             ~~~~~^~~~~~~~~~~~~~~~~
treearray.cpp:56:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |             scanf("%d %d %d",&l,&r,&v);
      |             ~~~~~^~~~~~~~~~~~~~~~~~~~~

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