1145A - Thanos Sort.cpp

#include<bits/stdc++.h>
#define endl '\n'
#define ll long long int
#define loop(i,a,b)           for(ll i=a;i<=b;++i)
#define pb                    push_back
#define F                     first
#define S                     second
#define mp                    make_pair
#define clr(x)                x.clear()
#define MOD                   1000000007
#define itoc(c)               ((char)(((int)'0')+c))
#define vl                    vector<ll>
#define SZ(x)                 (x).size()
#define all(p)                p.begin(),p.end()
#define mid(s,e)              (s+(e-s)/2)
#define sv()                  ll t,n; scanf("%lld",&t);n=t; while(t--)
#define tcase()               ll t,n; cin>>t;n=t; while(t--)
#define iscn(num)             scanf("%d",&num);
#define scn(num)              scanf("%lld ",&num);
using namespace std;
const ll INF = 2e18 + 99;
typedef pair<ll,ll> Pair;
typedef vector<ll> vec;
bool file=0,rt=1;
clock_t tStart ;
void FAST_IO();
////////////////////////
ll find_ans(vector<int> v , ll st, ll n){
bool flag = true ; ll cnt=1;
    for(int i=st ; i< n ; i++){
        if(v[i]>v[i+1]){
            flag=false ;
            break;
        }
        cnt++;
    }
    if(flag){
        return  cnt;
    }else{
        ll mid= (st+n)/2;
        ll temp=max(find_ans(v,st,mid),find_ans(v,mid+1,n));
        return temp;
    }

}
int main()
{

    FAST_IO();
    ////////////////////////
    ll n; scn(n);
    ll cnt=1,rem=0;
    vector<int> v;
    v.pb(0);
    for(int i=0; i< n ; ++i){
        scn(rem) ; v.pb(rem);
    } 
    printf("%lld\n",find_ans(v,1,n));

    ////////////////////////
    if(rt && file){
     printf("\nTime taken: %.6fs", (double)(clock() - tStart)/CLOCKS_PER_SEC);
    }
    return 0;
   }

void FAST_IO()
{
    // ios_base::sync_with_stdio(0);
    //cin.tie(NULL);
    //cout.tie(NULL);
    //cout.setf(ios::fixed);
    //cout.precision(2);
    if(rt && file){ tStart = clock(); }
    if(file){
    #ifndef _offline
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif
    }
}