题解 | 计算某字符出现次数

一种比较通用的解法提供给大家参考一下

#include <stdio.h>
#include<string.h>
#include<ctype.h>
int main()
{
    char arr[10002] = { 0 };
    int count = 0;
    int i = 0;
    fgets(arr, sizeof(arr), stdin);
    arr[strcspn(arr, "\n")] = '\0';    //去掉末尾可能的换行符
    char ch = 0;
    scanf("%c", &ch);
    if (isalpha(ch))
    {
        for (i = 0; arr[i] != '\0'; i++)
        {
            if ((ch == (arr[i] - 32) || ch == (arr[i] + 32)||ch==arr[i]))
            {
                count++;
            }
        }
    }
    else if (isdigit(ch))
    {
        for (i = 0; arr[i] != '\0'; i++)
        {
            if (arr[i] == ch)
            {
                count++;
            }
        }
    }
    printf("%d\n", count);
    return 0;
}