题解 | 计算某字符出现次数

#include <stdio.h>
#include <string.h>

int main() {
    int a, b;
    char c = 0;
    char c_bor = 0;
    char str[1000] = {0};
    int len = 0;
    int num = 0;
    scanf("%[^\n]\n", str);
    scanf("%c", &c);

    len = strlen(str);
    if ((c >= 'A'  && c <= 'Z') || (c >= 'a' && c <= 'z')) {//字母
        if (c >= 'a') {
            c_bor = c - ('a' - 'A');
        } else
            c_bor = c + ('a' - 'A');
        for (int i = 0; i < len; i++) {
            if (str[i] == c || str[i] == c_bor)
                num++;
        }
    } else {
        for (int i = 0; i < len; i++) {
            if (str[i] == c)
                num++;
        }
    }
    printf("%d", num);
    return 0;
}