# [383. Ransom Note](https://leetcode.com/problems/ransom-note/)

## 题目

Given two stings ransomNote and magazine, return true if ransomNote can be constructed from magazine and false otherwise.

Each letter in magazine can only be used once in ransomNote.

**Example 1**:

    Input: ransomNote = "a", magazine = "b"
    Output: false

**Example 2**:

    Input: ransomNote = "aa", magazine = "ab"
    Output: false

**Example 3**:

    Input: ransomNote = "aa", magazine = "aab"
    Output: true

**Constraints:**

- 1 <= ransomNote.length, magazine.length <= 100000
- ransomNote and magazine consist of lowercase English letters.

## 题目大意

为了不在赎金信中暴露字迹，从杂志上搜索各个需要的字母，组成单词来表达意思。

给你一个赎金信 (ransomNote) 字符串和一个杂志(magazine)字符串，判断 ransomNote 能不能由 magazines 里面的字符构成。

如果可以构成，返回 true ；否则返回 false 。

magazine 中的每个字符只能在 ransomNote 中使用一次。

## 解题思路

- ransomNote 和 magazine 都是由小写字母组成，所以用数组进行简单的字符统计

## 代码

````go
package leetcode

func canConstruct(ransomNote string, magazine string) bool {
	if len(ransomNote) > len(magazine) {
		return false
	}
	var cnt [26]int
	for _, v := range magazine {
		cnt[v-'a']++
	}
	for _, v := range ransomNote {
		cnt[v-'a']--
		if cnt[v-'a'] < 0 {
			return false
		}
	}
	return true
}
````