1862D - Ice Cream Balls - CodeForces Solution

  #include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mod 1000000007
#define int unsigned long long
#define ff first
#define endl "\n"
#define ss second
#define sz size()
#define mkp make_pair
#define yes cout<<"YES"<<endl;
#define no cout<<"NO"<<endl;
#define N 1e5+1
 int dp[2001][2001];
  bool check1(int n,int md) {
  int ans1=(md*(md-1))/2;
   //cout<<ans1<<" "<<md<<endl;endl;
   // cout<<"raj"<<endl;
 //  cout<<(md*(md-1))/2<<endl;
      if(((md*(md-1))/2)>n) {
        return true;
      }
      return false;
  }
  bool check(int n,int md) {
    int ans1=(md*(md-1))/2;
  
        if(md+ans1>=n) {
            return true;
        }
       else {
         return false;
       } 


  }
int32_t main ()
{
       int a,b,d,n,m,j,i,l,r,x,y,k,pos,g,c,x1,y1,y2,T,op1,op2,op,t,h,p,q;
 string s;  
     ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin>>t;
    //  t=1;
        while(t--) {
          cin>>n;
        int l=1;
         int r=1e11;
         int ans=1e11;
      //   cout<<"fuc"<<endl;
        while(l<=r) {
          
           int md=(l+r)/2;
        //  cout<<md<<endl;
            if(check1(n,md)) {
     //   yes
     //      cout<<md<<endl;
                r=md-1;
            }
           else {
      //    cout<<md<<" "<<r<<endl;endl; 
 //             yes
          if(check(n,md)) {
        //  yes
        //   cout<<md<<endl;
             int tmp=(md*(md-1))/2;
              int xx=0;
               int req=max(xx,(n-tmp));
              //  cout<<req+tmp<<endl;
              ans=min(ans,req+md);  
             l=md+1;
          } 
          else {
         //   yes
           //  cout<<md<<endl;
           // cout<<r<<endl;
             //cout<<md<<endl;
            l=md+1;
          }
}
        }   

          cout<<ans<<endl;
        }
    }