Frequency of a string in a C file

 
#include < stdio.h> 
#include < stdlib.h> 

void rech_caracteres(char characters[],int size)
{
 //open file in read mode
 FILE *file = fopen("C:/test.txt","r"); 
 char c;
 //array that saves repeats
 int repeat[size]; 
 //initialize to 0
 for(int i = 0 ; i < size; i++)
 repeat[i]=0; 
 //if the file exists
 if(file)
 {
 //as long as it's not the end of the file
 //read a character
 while((c=(char)getc(file))!=EOF)
 {
 //The read character is compare with
 //all characters searched
 for(int i = 0 ; i < size; i++)
 { 
 //if equal, increment
 //the counter associated with the character
 if(c==characters[i])
 repeat[i]++; 
 } 
 }
 //close file
 fclose(file); 
 //display
 printf("Number of repetitions:\n"); 
 for(int i = 0 ; i < size; i++)
 printf("\t%c : %d\n",characters[i],repeat[i]); 
 }
 else
 printf("\aERROR: Unable to open file: %s", file); 
}

int main()
{
 char string[]="a programmer"; 
 // sizeof(string)-1: size of the array
 // (-1 to not count the '\0')
 // '\0' indicates the end of the array
 rech_caracteres(string,sizeof(string)-1); 
 system("pause"); 
}