Cellular network

#include <bits/stdc++.h>
#define int long long
#define f first
#define s second
#define pb push_back
#define yes cout << "yes" << endl
#define no cout << "no" << endl

using namespace std;

bool madhav(int mid,vector<int>&city,vector<int>&tower,int n,int m)
{
    int cities=0,j=0,i=0;
       
           while(j<m && i<n)
          {
               if( abs( tower[j] - city[i] ) <= mid)
               {
                  i++;
                  cities++;
               }
               else j++; //break;
           }
          
       
       return cities>=n;
}

void solve() 
{
    int n,m;cin>>n>>m;
    vector<int>city(n),tower(m);
    for(int i=0;i<n;i++) cin>>city[i];
    for(int i=0;i<m;i++) cin>>tower[i];
    
    int low=0,high=2e9,ans=0;
    while(low<=high)
    {
        int mid = low + (high - low) / 2;
        if(madhav(mid,city,tower,n,m)==true)
        {
            ans=mid;
            high=mid-1;
        }
        else low=mid+1;
        //cout<<"\n";
   }
  
   cout<<ans<<endl;
}
    
signed main() 
{
    int t =1;
    //cin >> t;
    while (t--) 
    {
        solve();
    }

    return 0;
}