383. Ransom Note

383. Ransom Note

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Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true if the ransom note can be constructed from the magazines ; otherwise, it
will return false.
Each letter in the magazine string can only be used once in your ransom note.
Note:

You may assume that both strings contain only lowercase letters.

canConstruct("a", "b") -> false
canConstruct("aa", "ab") -> false
canConstruct("aa", "aab") -> true

Seen this question in a real interview before?

题意：

这个题叫绑架信是模仿绑架信的写法
我们信中的内容要从杂志上剪出来，所以确保我们信中的每一个字在杂志上都要有

算法思路：

首先先把信和杂志上的每一个字符的出现次数统计在一个数组中
然后比较信中的字符出现的次数，如果有大于杂志上的返回失败，否则成功

代码：

package easy;

import javax.print.attribute.standard.RequestingUserName;

public class RansomNote {

public boolean canConstruct(String ransomNote, String magazine) {

int[] ran = new int[26];
int[] mag = new int[26];

for(int i=0; i<ransomNote.length(); i++){
ran[ransomNote.charAt(i) - 'a']++;
}

for(int i=0; i<magazine.length(); i++){
mag[magazine.charAt(i) - 'a']++;
}

for(int i=0; i<ran.length; i++){
if(ran[i] > mag[i]){
return false;
}
}

return true;
}

}