题解 | 字符串构造判定-Java

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param ransomNote string字符串
     * @param magazine string字符串
     * @return bool布尔型
     */
    public boolean canConstruct (String ransomNote, String magazine) {
        // write code her
        HashMap<Character, Integer> hmS = new HashMap<>();
        HashMap<Character, Integer> hmT = new HashMap<>();

        for (int i = 0; i < ransomNote.length(); i++) {
            char c = ransomNote.charAt(i);
            hmS.put(c, hmS.getOrDefault(c, 0) + 1);
        }

        for (int j = 0; j < magazine.length(); j++) {
            char c = magazine.charAt(j);
            hmT.put(c, hmT.getOrDefault(c, 0) + 1);
        }

        for (Character k : hmS.keySet()) {
            if (hmT.containsKey(k) && hmS.get(k) <= hmT.get(k)) {
                continue;
            } else {
                return false;
            }
        }

        return true;

    }
}