Increasing Subsequence.cpp

#include<bits/stdc++.h>
using namespace std;
 
#define   fi(a,b) for(int i=a;i<b;i++)
#define   fj(a,b) for(int j=a;j<b;j++)
#define   ff first
#define   ss second
#define   ll long long
#define   ld long double
#define   ull unsigned long long
#define   bp(x) __builtin_popcount(x)
#define   pr(x) for(auto it: x) cout<<it<<" "; cout<<endl;
#define   getMax(x) max_element(x.begin(),x.end())
#define   getMin(x) min_element(x.begin(),x.end())
#define   endl "\n"
typedef   vector<int> vi;
typedef   vector< pair<int,int> > vii;
typedef   vector<long long> vl;
typedef   pair<int,int> pii;
typedef   pair<ll,ll> pll;
typedef   vector< pair<ll,ll> > vll;
//int dx[]={1,0,-1,0};
//int dy[]={0,1,0,-1};
//int dx[]={-1,0,1,1,1,0,-1,-1};
//int dy[]={-1,-1,-1,0,1,1,1,0};
 
const int MOD = 1e9 + 7;
 
//Time Complexity n(log(n))
int CeilIndex(vector<int>& v, int l, int r, int key) { 
    while (r - l > 1) { 
        int m = l + (r - l) / 2; 
        if (v[m] >= key) 
            r = m; 
        else
            l = m; 
    } 
    return r; 
} 
  
int LongestIncreasingSubsequenceLength(vector<int>& v) { 
    if (v.size() == 0) 
        return 0;
    vector<int> tail(v.size(), 0); 
    int length = 1; 
  
    tail[0] = v[0]; 
    for (size_t i = 1; i < v.size(); i++) {  
        if (v[i] < tail[0]) 
            tail[0] = v[i]; 
        else if (v[i] > tail[length - 1]) 
            tail[length++] = v[i]; 
        else
            tail[CeilIndex(tail, -1, length - 1, v[i])] = v[i]; 
    } 
    return length; 
} 
 
void nikal_pehli_fursat_mai(){
    int n;
    cin>>n;
    vi v(n);
    fi(0,n) cin>>v[i];
    cout<<LongestIncreasingSubsequenceLength(v)<<endl;
}
 
int main(){
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif
    ios::sync_with_stdio(0);
    cin.tie(0);
    int tc=1; 
    // cin>>tc;
    while(tc--){
    nikal_pehli_fursat_mai();
    }
}