Submission #1223186

#	Time	Username	Problem	Language	Result	Execution time	Memory
1223186		fermat	Birthday gift (IZhO18_treearray)	C++20	100 / 100	1381 ms	57776 KiB

treearray

#include <bits/stdc++.h>
 
#define fr first
#define sc second
#define mk make_pair
#define pb emplace_back
#define all(s) s.begin(), s.end()
 
using namespace std;

const int N = 2e5 + 5;

int n, m, q, x, y, up[20][N], h[N], a[N], type, l, r;

vector < vector <int> > g; 

void dfs (int v, int p = 0)
{
 h[v] = h[p] + 1;
 
 up[0][v] = p;
 for (int i = 1; i < 20; i++)
  up[i][v] = up[i - 1][ up[i - 1][v] ];
  
 for (auto to : g[v])
 {
  if (to == p) continue;
  dfs(to, v);
 }
}
int lca (int a, int b)
{
 if(h[a] > h[b]) swap(a, b);
 
 int cnt = h[b] - h[a];
 
 for (int i = 19; i >= 0; i--)
 {
  if (cnt & (1 << i) )
   b = up[i][b];
 }
 if (a == b) return a;
 
 assert( h[a] == h[b] );
 
 for (int i = 19; i >= 0; i--)
 {
  if (up[i][a] != up[i][b])
   a = up[i][a], b = up[i][b];
 }
 return up[0][a];
}
set < pair <int, int> > st, st2;

main() 
{
 cin >> n >> m >> q;
 g.resize(n + 1);
 
 for (int i = 1; i < n; i++)
 {
  scanf("%d%d", &x, &y);
  g[x].pb(y);
  g[y].pb(x);
 }
 dfs(1);
 
 for (int i = 1; i <= m; i++)
 {
  scanf("%d", &a[i]);
  if (i > 1)
   st.insert( mk( lca( a[i - 1], a[i] ), i - 1 ) );
   
  st2.insert( mk(a[i], i) );
 }
 while (q--)
 {
  scanf("%d%d%d", &type, &l, &r);
  
  if (type == 1){
   st2.erase( mk(a[l], l) );
   if (l > 1)
    st.erase( mk( lca( a[l - 1], a[l] ), l - 1 ) );
   if (l < m)
    st.erase( mk( lca( a[l], a[l + 1] ), l ) );
   a[l] = r;
   if (l > 1)
    st.insert( mk( lca( a[l - 1], a[l] ), l - 1 ) );
   if (l < m)
    st.insert( mk( lca( a[l], a[l + 1] ), l ) );
   st2.insert( mk(a[l], l) );
  }
  else{
   scanf("%d", &x);
   auto it = st2.lower_bound( mk(x, l) );
   if ( it != st2.end() && it->fr == x && it->sc <= r )
    printf("%d %d\n", it->sc, it->sc);
   else
   {
    auto it = st.lower_bound( mk( x, l ) );
    if ( it != st.end() && it->fr == x && it->sc + 1 <= r )
     printf("%d %d\n", it->sc, it->sc + 1);
    else
     printf("-1 -1\n");
   }
  }
 }
}

Compilation message (stderr)

treearray.cpp:55:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   55 | main()
      | ^~~~
treearray.cpp: In function 'int main()':
treearray.cpp:62:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |   scanf("%d%d", &x, &y);
      |   ~~~~~^~~~~~~~~~~~~~~~
treearray.cpp:70:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |   scanf("%d", &a[i]);
      |   ~~~~~^~~~~~~~~~~~~
treearray.cpp:78:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |   scanf("%d%d%d", &type, &l, &r);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
treearray.cpp:94:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |    scanf("%d", &x);
      |    ~~~~~^~~~~~~~~~

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