I got this(ADATREE — Ada and Trees) problem from morass blog segment tree section. I stuck to analyzing the both time complexity and memory complexity of this problem in the worst case for this AC solution.
My Solution: ~~~~~ /// BISMILLAHIR RAHMANIR RAHEEM
include<bits/stdc++.h>
using namespace std;
define MUHAMMAD ios::sync_with_stdio(0);cin.tie(0);
define all(x) (x).begin(), (x).end()
using ll = long long; const ll N = 3e5 + 5;
vector < ll > tr[N<<2];
ll n; ll arr[N]; ll q; ll x;
vector < ll > merge( vector a , vector b ){
vector order; while( a.size() and b.size() ){ int x = a.back(); int y = b.back(); if ( x <= y ) { order.push_back ( x ); a.pop_back(); } else { order.push_back ( y ); b.pop_back(); } }
while(a.size()) order.push_back(a.back()) , a.pop_back(); while(b.size()) order.push_back(b.back()) , b.pop_back(); return order; }
void build(ll u, ll st, ll en) {
if (st==en) {
tr[u].push_back ( arr[st] );
}
else {
ll mid = (st+en)/2;
build(2*u, st, mid);
build(2*u+1, mid+1, en);
vector < ll > bame = tr[2*u];
vector < ll > dane = tr[2*u+1];
reverse ( all ( bame ) );
reverse ( all ( dane ) );
vector<ll> res = merge( bame , dane );
reverse ( all ( res ) );
while(res.size()){
tr[u].push_back ( res.back() );
res.pop_back();
}
}}
ll query(ll u, ll st, ll en, ll l, ll r) {
ll bame , dane , res;
if (r<st || en<l) return 0;
if (l<=st && en<=r){
ll lo = st;
ll hi = en;
ll mx = 0;
while(lo<=hi){
ll mid = (lo+hi)>>1;
ll cur = tr[u][mid-st];
if ( cur > x ) hi = mid - 1;
else{
lo = mid + 1;
mx = max ( mx , cur );
}
}
return mx;
}
ll mid = (st+en)/2;
bame = query(2*u, st, mid, l, r);
dane = query(2*u+1, mid+1, en, l, r);
return max(bame,dane);}
void Solution ( int tc ){
cin >> n >> q; for ( int i = 1 ; i <= n ; ++i ) cin >> arr[i]; build ( 1 , 1 , n ); for ( int i = 1 ; i <= q ; i++ ){ ll l , r; cin >> l >> r >> x; l++; r++; ll res = query ( 1 , 1 , n , l , r ); cout << res << "\n"; } return; }
int main() { MUHAMMAD;
int testcase = 1 , tc = 0;
/// cin >> testcase;
for ( int i = 1 ; i <= testcase ; ++i ){
Solution( ++tc );
}
return 0;}
/*
Explanation:
Time :
Alhamdulillah */
~~~~~
Can anyone help me to calculate this. Thanks in advance.



