牛客网 HJ2 计算某字符出现次数

#include <stdio.h>
#include <string.h>
#include <assert.h>
int func(char* str, char ch)
{
    assert(str);
    int len = strlen(str);
    int count = 0;
    for (int i = 0; i < len; i++)
    {
        if (str[i] >= '0' && str[i] <= '9')
        {
            if (ch == str[i])
            {
                count++;
            }
        }
        else if ((str[i] >= 'a' && str[i] <= 'z')|| (str[i] >= 'A' && str[i] <= 'Z'))
        {
            if (!(ch>='0'&&ch<='9') && (ch == str[i] || ch == (str[i] - 32) || ch == (str[i] + 32)))
            {
                count++;
            }
        }
       
    }
    return count;
}

int main()
{
    char arr[1001] = {0};
    char ch = 0;
    int ret = 0;
    int j = 0;
    while((ret = getchar())!='\n')
    {
        arr[j++] = ret;
    }
    scanf("%c",&ch);
    int ret2 = func(arr,ch);
    printf("%d\n",ret2);
    return 0;
}