题解 | #计算某字符出现次数#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    private static int countStr(String str, String ch) {
        char[] chars = ch.toCharArray();
        Character c = chars[0];

        char[] chars1 = str.toLowerCase().toCharArray();
        int count = 0;

        for (int i = 0; i < chars1.length; i++) {
            if (chars1[i] == Character.toLowerCase(c)) {
                count += 1;
            }
        }
        return count;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        String s = in.nextLine();
        String s1 = in.nextLine();
        System.out.println(Main.countStr(s, s1));
    }
}