/*****************

實現讀取檔案，並統計每個字元出現的個數

*****************/


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

unsigned long file_size;
unsigned int frequency_count[512];
FILE* infilepointer;

void get_frequency_count ()
{

	for (unsigned int i = 0; i < file_size; i++)
	{
		frequency_count[getc(infilepointer)]++; 
                                    //getc (infilepointer)從檔案指標指向的檔案讀入一個字元
	}                                           }


bool func(const char* infilename)
{
	if(( infilepointer = fopen(infilename, "rb") ) != NULL)
	{
		fseek( infilepointer, 0L, 2);//將檔案位置指標指向檔案末尾
		file_size = (unsigned long) ftell(infilepointer);

		fseek( infilepointer, 0L, 0);
		get_frequency_count ();

		fclose (infilepointer);

		return 1;
	}

	else
	{
		printf("Error! can't open %s",infilename);
		return 0;
	}
}
int main()
{
	func("C:\\Users\\Pacer95\\Desktop\\12.txt");
	printf("%d,",frequency_count[48]);
}
 

12.txt裡的內容 

統計出0字元的個數，如圖