242.有效的字母异位词 1002. 查找常用字符 （哈希表）-补昨日

242.有效的字母异位词

Accept

题目为小写字母，自定义长度26的数组构成hash数组
java遍历字符串：char c = str1.charAt(i);

public class test {
    public static void main(String[] args) {
        Scanner scanner =new Scanner(System.in);
        String str1 = scanner.next();
        String str2 = scanner.next();
        int []hash = new int[26];
        for (int i = 0; i < str1.length(); i++) {
            char c = str1.charAt(i);
            hash[c - 'a'] ++;
        }
        for (int i = 0; i < str2.length(); i++) {
            hash[str2.charAt(i) - 'a']--;
        }
        int i;
        for (i = 0; i < 26; i++) {
            if (hash[i]!= 0) {
                System.out.println(false);
                break;
            }
        }
        if (i == 26) System.out.println(true);

    }
    
}

1002. 查找常用字符

Accept

构造二维哈希表，统计出现次数后取一列最小值
java while输入字符串如何结束？

public class test {
    public static void main(String[] args) {

        Scanner scanner =new Scanner(System.in);
        List<String> list = new ArrayList<>();
        List<String> res = new ArrayList<>();
//        while (scanner.hasNext()){
//            list.add(scanner.next());
//
//        }
        list.add("ll");
        list.add("ll");
        list.add("ll");
        int size = list.size();
        int temp[][] = new int[size][26];
        for (int j = 0; j < size; j++){
            for (int i = 0; i < list.get(j).length(); i++) {
                temp[j][list.get(j).charAt(i) - 'a'] ++;
            }
        }
        for (int i = 0; i < 26; i++) {
            int min = Integer.MAX_VALUE;
            for (int j = 0; j < size; j++) {
                min = Math.min(temp[j][i],min);
            }
            for (int k = 0; k < min; k++){
                char c = (char) (i + 'a');
                res.add(String.valueOf(c));
            }
        }
        res.forEach(System.out::print);
    }

}