Merge pull request #207 from gostool/leetcode0383

Leetcode0383

leetcode/0383.Ransom-Note/383.Ransom Note.go

@@ -0,0 +1,18 @@
+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
+}

leetcode/0383.Ransom-Note/383.Ransom Note_test.go

@@ -0,0 +1,51 @@
+package leetcode
+
+import (
+	"fmt"
+	"testing"
+)
+
+type question383 struct {
+	para383
+	ans383
+}
+
+// para 是参数
+type para383 struct {
+	ransomNote string
+	magazine   string
+}
+
+// ans 是答案
+type ans383 struct {
+	ans bool
+}
+
+func Test_Problem383(t *testing.T) {
+
+	qs := []question383{
+
+		{
+			para383{"a", "b"},
+			ans383{false},
+		},
+
+		{
+			para383{"aa", "ab"},
+			ans383{false},
+		},
+
+		{
+			para383{"aa", "aab"},
+			ans383{true},
+		},
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 383------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans383, q.para383
+		fmt.Printf("【input】:%v    【output】:%v\n", p, canConstruct(p.ransomNote, p.magazine))
+	}
+	fmt.Printf("\n\n\n")
+}

leetcode/0383.Ransom-Note/README.md

@@ -0,0 +1,64 @@
+# [383. Ransom Note](https://leetcode-cn.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
+}
+````