出现次数统计

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
void max_appear(int a[], int len);

int main() 
{   

    int a[10000] = {2, 3, 4, 2, 2, 5, 3, 4, 2, 4};
    int i = 0;
    int len = 0;
    srand((unsigned)time(NULL));
    for(i = 0; i < 10000; i++)
    {
        a[i] = rand() % 10;
    }
    len = sizeof(a) / sizeof(a[0]);
    max_appear(a, len);

    system("pause");
    return 0;
}

void max_appear(int a[], int len)
{
    int i = 0, j = 0;
    int num = 0;
    int *count = NULL;
    int bop = 0;
    count = (int*)calloc((num + 2), sizeof(int));

    for(i = 0; i < len; i++)
    {   
        for(j = 0; j < i; j++)
        {    
            bop = 0;
            if(a[j] == a[i])
            {   
                bop = 1;
                break;            
            }            
        }
        if(bop == 1)
        {
            continue;
        }

        count[num] = a[i];

        for(j = i; j < len; j++)
        {
            if(a[i] == a[j])
            {
                count[num + 1]++;
            }
        }        
        num += 2;
        count = (int*)realloc(count, (num + 2) * sizeof(int));
        count[num + 1] = 0;
    }

    for(i = 0; i < num; i += 2)
    {
        printf("数字%d的个数是%d.\n", count[i], count[i + 1]);
    }

    free(count);
    count = NULL;
}