103 - 第三周作业

Week_02/id_103/HashTable/P242.go

@@ -0,0 +1,48 @@
+package HashTable
+
+//已通过
+func IsAnagram(s string, t string) bool {
+	if len(s) != len(t){
+		return false
+	}
+	sb :=[]byte(s)
+	collectionMap := map[byte]int{}
+	for i := 0; i< len(sb);i++  {
+		value,ok := collectionMap[sb[i]]
+		if !ok {
+			collectionMap[sb[i]] = 1
+		}else{
+			collectionMap[sb[i]] = value + 1
+		}
+	}
+
+	st := []byte(t)
+	for i := 0; i< len(st);i++  {
+		value,ok := collectionMap[st[i]]
+		if !ok {
+			return false
+		}else{
+			if value == 0{
+				return false
+			}
+			collectionMap[st[i]] = value - 1
+		}
+	}
+	return true
+}
+
+func IsAnagram2(s string, t string) bool {
+	tmpA,tmpB :=make([]int,26),make([]int,26)
+	for i:=0;i<len(s);i++ {
+		tmpA[s[i]-'a']++
+	}
+	for i:=0;i<len(t);i++ {
+		tmpB[t[i]-'a']++
+	}
+	for i:=0;i<26;i++ {
+		if tmpA[i] != tmpB[i] {
+			return false
+		}
+	}
+	return true
+}

Week_02/id_103/HashTable/P671.go

@@ -0,0 +1,41 @@
+package HashTable
+
+import "math"
+//Finished
+var res = -1
+func findSecondMinimumValue(root *TreeNode) int {
+	min := minValue(root)
+	res = math.MaxInt64
+	helpFind(root,min)
+	if res == math.MaxInt64{
+		return -1
+	}
+	return res
+}
+
+func helpFind(root *TreeNode, min int)  {
+	if root != nil{
+		if root.Val > min && root.Val < res{
+			res = root.Val
+		}
+		helpFind(root.Left,min)
+		helpFind(root.Right,min)
+	}
+}
+
+func minValue(root *TreeNode) int {
+	if root.Left == nil && root.Right == nil{
+		return root.Val
+	}
+	if root.Left == nil{
+		return minValue(root.Right)
+	}
+	if root.Right == nil{
+		return minValue(root.Left)
+	}
+	if root.Left.Val < root.Right.Val{
+		return minValue(root.Left)
+	}else {
+		return minValue(root.Right)
+	}
+}

Week_02/id_103/HashTable/P692.go

@@ -0,0 +1,40 @@
+package HashTable
+
+import (
+	"sort"
+)
+//测试没过，因为顺序问题
+func TopKFrequent(words []string, k int) []string {
+	collectionMap := map[string]int{}
+
+	for _, v := range words {
+		if intV,ok:=collectionMap[v];ok{
+			collectionMap[v] = intV +1
+		}else{
+			collectionMap[v] = 1
+		}
+	}
+	res := []string{}
+	counts := make([]int,0)
+	for _, v := range collectionMap {
+		counts = append(counts, v)
+	}
+	sort.Ints(counts)
+	searchResult := counts[len(counts)-k:]
+
+	for k,v := range collectionMap {
+		if help(searchResult,v){
+			res = append(res, k)
+		}
+	}
+	return res
+}
+
+func help (arr []int,compare int) bool{
+	for e := range arr {
+		if compare == arr[e]{
+			return true
+		}
+	}
+	return false;
+}

Week_02/id_103/HashTable/TreeNode.go

@@ -0,0 +1,7 @@
+package HashTable
+
+type TreeNode struct {
+	Val int
+	Left *TreeNode
+	Right *TreeNode
+}