题解 | #计算某字符出现次数#

public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    while (in.hasNext()) {
        String words = in.nextLine();
        String word = in.nextLine();
        run(words,word);
    }
} 
public static void run(String words,String word) {
    char c = word.charAt(0);
    if (c >='a' && c<= 'z'){
        String newWord=  words.replace(word,"");
        String newWord1=  words.replace(word.toUpperCase(),"");
        System.out.println(words.length()*2 - newWord.length() - newWord1.length());
    }else if (c >='A' && c<= 'Z'){
        String newWord=  words.replace(word,"");
        String newWord1=  words.replace(word.toLowerCase(),"");
        System.out.println(words.length()*2 - newWord.length() - newWord1.length());
    }else {
        String newWord=  words.replace(word,"");
        System.out.println(words.length() - newWord.length());
    } 
}