LeetCode/com/zerroi/leetcode/Three18/CanConstruct.java

package com.zerroi.leetcode.Three18;

import java.util.HashMap;
import java.util.Map;

public class CanConstruct {
    public static void main(String[] args) {
        SolutionFirst solutionFirst = new SolutionFirst();
        boolean res = solutionFirst.canConstruct("aa", "aab", 1);
        System.out.println("res = " + res);

    }
}

class SolutionFirst {
    public boolean canConstruct(String ransomNote, String magazine) {
        if (magazine.length() < ransomNote.length()) return false;

        Map<Character, Integer> map = new HashMap<>();
        for (char c : magazine.toCharArray()) {
            if (map.containsKey(c)) {
                map.put(c, map.get(c) + 1);
            } else {
                map.put(c, 1);
            }
        }

        for (char c : ransomNote.toCharArray()) {
//            如果magazine中不包涵ransomNote中的某一个字符
            if (!map.containsKey(c)) {
                return false;
            } else {
                Integer i = map.get(c);
                if (i <= 0) {
                    return false;
                }
                else map.put(c, i-1);
            }

        }

        return true;
    }

    public boolean canConstruct(String ransomNote, String magazine, int i) {
        char[] ransomNoteCharArray = ransomNote.toCharArray();
        char[] magazineCharArray = magazine.toCharArray();
        int[] count = new int[26];
        for (char c : magazineCharArray) {
            count[c - 'a']++;
        }

        for (char c : ransomNoteCharArray) {
            count[c - 'a']--;
            if (count[c - 'a'] < 0) return false;
        }

        return true;
    }
}