//array_size.c
#include "stdio.h"
#define N 5

int main(){
 int arr[N];

 printf("size of arr=%lu", sizeof(arr)/sizeof(int));
 return 0;
}
//--end

//random.c
#include "stdio.h"
#include "stdlib.h"
#include <time.h>
#define N 10

#define MAX 3
#define MIN 1

int main(){
 time_t t;
 int i,r;
 srand((unsigned) time(&t)); // srand is must, or it create SAME number
 for (i=0; i<N; i++){
  r=rand()%(MAX-MIN+1)+MIN;
  printf("%d ", r);
 }

 return 0;
}
//--end

//dup_time.c
#include "stdio.h"
#define N 5

int main(){
 int arr[N]={1,1,2,3,4};
 int brr[N];
 int crr[N];
 int i,j;
 int n=sizeof(arr)/sizeof(int);

 for (i=0; i<n; i++){
  brr[i]=arr[i];
  crr[i]=0;
 }

 for (i=0; i<n; i++){
  for (j=0; j<n; j++){
   if (arr[j] == brr[i]){
    crr[i]++;
   }
  }
 }

 for (i=0; i<n;i++){
  printf("%d ", crr[i]);
 }
 return 0;
}
//--end


//ave
#include "stdio.h"
#include "stdlib.h"
#include <time.h>

#define N 10
#define MIN 60
#define MAX 90

int main(){
 int arr[N];
 time_t t;
 int i,r;
 int s=0;

 srand((unsigned) time(&t)); // srand is must, or it create SAME number

 for (i=0; i<N; i++){
  arr[i]=rand()%(MAX-MIN+1)+MIN;
  s+=arr[i];
 } 

 printf("%d\n",s/N);

}