题解 | #计算某字符出现次数#

#include <stdio.h>
#include <ctype.h>
char* s_gets(char* st, int n) {
    char* ret_val;
    int i = 0;

    ret_val = fgets(st, n, stdin);
    if (ret_val) {
        while (st[i] != '\n' && st[i] != '\0')
            i++;
        if (st[i] == '\n')
            st[i] = '\0';
        else
            while (getchar() != '\n')
                continue;      
    }
    return ret_val;
}
int main() {
    char str[1000];
    char c;
    int count = 0;
    s_gets(str, 1000);
    scanf("%c", &c);
    for (int i = 0; str[i] != '\0' && str[i] != '\n'; i++) {
        if (isalpha(c)) {
            if (tolower(c) == tolower(str[i]))
                count++;
        } else {
            if (c == str[i])
                count++;
        }
    }
    printf("%d", count);
    return 0;
}