所以，我实现的直方图，基本上把一个字符串作为输入，把它分成单词，然后把单词的长度作为索引，输出是一个整数数组。a[p]++，如果strlen（s）==p基本上。我的代码要么打印一个零，要么根本不工作。为什么？代码是：

#include <stdio.h>
#define BUFFER_SIZE 1024
#define array_size(_S) 5000 //didn't want to edit code, this used to be a formula.

//an input function I coded when I was a beginner.
void input_str(char * str, int delimeter, int bound)
{
    int inpchar;
    register int incvar = 0;
    while (incvar < bound)
    {
        inpchar = getchar();
        if(inpchar == '\n' || inpchar == delimeter)
        {
            *(str+incvar) = '\0';
             return;
        }
        *(str+(incvar++))=inpchar;
    }
    *(str+incvar) ='\0';
}

//old code I used
int lenstr(char * str)
{
    register int varinc = 0;
    while( *(str + varinc) != '\0')
    {
        varinc++;
    }
    return varinc;
}

void xprintf(const char *s)
{
    int counter = 0;
    while ( *(s + counter) != '\0')
    {
        putchar(*(s + counter));
        counter++;
    }
}

void initialize(int **a, unsigned int len)
{
    int counter = 0;
        while(counter < len)
        {
            *(a + counter) = 0;
             counter++;
        }
}

int main(void)
{
    char inp_str[BUFFER_SIZE + 1];
    printf("Enter full string.\n");
    input_str(inp_str,-1,BUFFER_SIZE);
    int ncounter = 0;
    int ecounter = 0;
    int frequency_array[ array_size(inp_str)];
    intialize (frequency_array, array_size(inp_str));
    int real_length = lenstr(inp_str);
    while (ncounter <= real_length)
    {
        while(*(inp_str + (ncounter + ecounter)) != ' ' && *(inp_str +(ncounter + ecounter)) !='\0')
        {
            ecounter++;
        }
        frequency_array[ecounter]++;
        ncounter = ncounter + ecounter + 2;
        ecounter = 0;
    }
    ncounter = 0;
    while (ncounter < array_size(inp_str))
    {
        putchar(*(frequency_array + ncounter) + '0');
        ncounter++;
    } 
    return 0;
}

现在，它只是segfaults。