题解 | #计算某字符出现次数#

#include <stdio.h>
#include <string.h>
int main() {
    char str[1000] = {0};
    char ch = 0;
    int len = 0;
    int num = 0;
    gets(str);
    scanf("%c", &ch);

    while (str[len] != '\0') {
        if ((ch >= 65 && ch <= 90) || (ch >= 97 && ch <= 122)) {  // 字母
            if (str[len] == ch || str[len] == ch + 32
               || str[len] == ch - 32) {
                num++;
                len++;
                continue;
            }
            len++;
        } else {  // 非字母
            if (str[len] == ch) {
                num++;
                len++;
                continue;
            }
            len++;
        }
    }
    printf("%d", num);
    return 0;
}