UDP_Linux program in C

UDP_Server.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <unistd.h>
#include <math.h>

int main(){
 int sid = socket(AF_INET, SOCK_DGRAM, 0);
 struct sockaddr_in s, c;
 s.sin_family = AF_INET;
 s.sin_port = htons(6666);
 s.sin_addr.s_addr = inet_addr("127.0.0.1");
 bind(sid, (struct sockaddr *)&s, sizeof(s));
 int l = sizeof(c);
 while(1){
  char arr[100000];
  char brr[100000] = {'0'};
  int n = recvfrom(sid, (void *)arr, sizeof(arr), 0, (struct sockaddr *)&c, &l) - 1;
  printf("Dataword: %s\n", arr);
  int i,j,r = 0;
  for(i=1;;i++){
   if((int)pow(2,i)-i > n){
    r = i;
    break;
   }
  }
  int c1=0;
  for(i=0;i<n+r;i++)
  {
   float p=log2(i+1);
   if(p==(int)p)
    continue;
   brr[i]=arr[c1++];
  }
  for(i=1;i<=n+r;i*=2)
  {
   int count=0;
   j=i-1;
   while(j<n+r)
   {
    int cur=j;
    for(j=cur;j<(cur+i);j++)
    {
     if(j>=(n+r))
      break;
     if(brr[j]=='1')
      count++;
    }
    j+=i;
   }
   if(count%2==1)
    brr[i-1]='1';
   else
    brr[i-1]='0';
  }
  brr[n+r]='\0';
  printf("Codeword: %s\n",brr);
  sendto(sid, (void *)brr, strlen(brr)+1, 0, (struct sockaddr *)&c, sizeof(c));
 }
 return 0;
}

UDP_Client.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <unistd.h>

int main(){
 int sid = socket(AF_INET, SOCK_DGRAM, 0);
 struct sockaddr_in s;
 s.sin_family = AF_INET;
 s.sin_port = htons(6666);
 s.sin_addr.s_addr = inet_addr("127.0.0.1");
 //bind(sid, (struct sockaddr *)&s, sizeof(s));
 char arr[100000];
 printf("Enter a binary string:\n");
 scanf("%s", arr);
 sendto(sid, (void *)arr, strlen(arr)+1, 0, (struct sockaddr *)&s, sizeof(s));
 int l = sizeof(s);
 recvfrom(sid, (void *)arr, sizeof(arr), 0, (struct sockaddr *)&s, &l);
 printf("%s\n", arr);
 return 0;
}