feat:2021年05月26日14:49:20

Author: 陈世伟

leetcode/1047.删除字符串中的所有相邻重复项[stack]/remove_duplicates.go renamed to leetcode/1047.删除字符串中的所有相邻重复项/remove_duplicates.go

@@ -1,13 +1,17 @@
-package _047_删除字符串中的所有相邻重复项_stack_
+package _047_删除字符串中的所有相邻重复项
+
+import "fmt"
 
 func removeDuplicates(S string) string {
 	var stack []byte
 	for i := 0; i < len(S); i++ {
 		if len(stack) > 0 && stack[len(stack)-1] == S[i] {
+			fmt.Println(stack[len(stack)-1], S[i], string(stack[:len(stack)-1]))
 			stack = stack[:len(stack)-1]
 			continue
 		}
 		stack = append(stack, S[i])
 	}
+	fmt.Println(string(stack))
 	return string(stack)
 }

leetcode/1047.删除字符串中的所有相邻重复项[stack]/remove_duplicates_test.go renamed to leetcode/1047.删除字符串中的所有相邻重复项/remove_duplicates_test.go

@@ -1,4 +1,4 @@
-package _047_删除字符串中的所有相邻重复项_stack_
+package _047_删除字符串中的所有相邻重复项
 
 import "testing"
 

leetcode/17.电话号码的字母组合/letterCombinations.go

@@ -0,0 +1,49 @@
+package _7_电话号码的字母组合
+
+var letterMap = []string{
+	"",     // 0
+	"",     // 1
+	"abc",  // 2
+	"def",  // 3
+	"ghi",  // 4
+	"jkl",  // 5
+	"mno",  // 6
+	"pqrs", // 7
+	"tuv",  // 8
+	"wxyz", // 9
+}
+
+func letterCombinations(digits string) []string {
+	var (
+		paths []string
+		path  []byte
+		fn    func(digits string, startIdx int)
+	)
+	if len(digits) == 0 {
+		return nil
+	}
+
+	fn = func(digits string, startIdx int) {
+		if len(path) == len(digits) {
+			tmp := make([]byte, len(digits), len(digits))
+			copy(tmp, path)
+			paths = append(paths, string(tmp))
+			return
+		}
+
+		world := letterMap[digits[startIdx]-'0']
+		// for 横向遍历
+		for _, v := range world {
+			path = append(path, byte(v))
+			// 递归纵向遍历
+			fn(digits, startIdx+1)
+			// 回溯不断调整结果集
+			path = path[:len(path)-1]
+		}
+
+	}
+
+	fn(digits, 0)
+
+	return paths
+}

leetcode/17.电话号码的字母组合/letterCombinations_test.go

@@ -0,0 +1,29 @@
+package _7_电话号码的字母组合
+
+import (
+	"reflect"
+	"testing"
+)
+
+func Test_letterCombinations(t *testing.T) {
+	type args struct {
+		digits string
+	}
+	tests := []struct {
+		name string
+		args args
+		want []string
+	}{
+		{name: `输入：digits = "23"
+输出：["ad","ae","af","bd","be","bf","cd","ce","cf"]`, args: args{digits: "23"}, want: []string{
+			"ad", "ae", "af", "bd", "be", "bf", "cd", "ce", "cf",
+		}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := letterCombinations(tt.args.digits); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("letterCombinations() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

leetcode/216.组合总和III/combinationSum3.go

@@ -0,0 +1,33 @@
+package _16_组合总和III
+
+func combinationSum3(k int, n int) [][]int {
+
+	var (
+		fn    func(k, n, startIdx int)
+		paths [][]int
+		path  []int
+		// 计算sum
+		sum int
+	)
+	fn = func(k, n, startIdx int) {
+		if len(path) == k { // 符合3个数
+			if sum == n { // 判断总和
+				tmp := make([]int, len(path), cap(path))
+				copy(tmp, path)
+				paths = append(paths, tmp)
+			}
+			return
+		}
+		for i := startIdx; i <= 9-(k-len(path))+1; i++ {
+			path = append(path, i)
+			sum += i
+			fn(k, n, i+1)
+			path = path[:len(path)-1]
+			sum -= i
+		}
+	}
+
+	fn(k, n, 1)
+
+	return paths
+}

leetcode/216.组合总和III/combinationSum3_test.go

@@ -0,0 +1,30 @@
+package _16_组合总和III
+
+import (
+	"reflect"
+	"testing"
+)
+
+func Test_combinationSum3(t *testing.T) {
+	type args struct {
+		k int
+		n int
+	}
+	tests := []struct {
+		name string
+		args args
+		want [][]int
+	}{
+		{name: `输入: k = 3, n = 7 输出: [[1,2,4]]`, args: args{
+			k: 3,
+			n: 7,
+		}, want: [][]int{{1, 2, 4}}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := combinationSum3(tt.args.k, tt.args.n); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("combinationSum3() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

leetcode/39.组合总和/combinationSum.go

@@ -0,0 +1,35 @@
+package _9_组合总和
+
+func combinationSum(candidates []int, target int) [][]int {
+	var (
+		paths [][]int
+		path  []int
+		sum   int
+		fn    func(candidates []int, target int, startIdx int)
+	)
+
+	fn = func(candidates []int, target int, startIdx int) {
+		if sum > target {
+			return
+		}
+
+		if sum == target {
+			tmp := make([]int, len(path))
+			copy(tmp, path)
+			paths = append(paths, tmp)
+			return
+		}
+
+		for i := startIdx; i < len(candidates); i++ {
+			path = append(path, candidates[i])
+			sum += candidates[i]
+			fn(candidates, target, i)
+			path = path[:len(path)-1]
+			sum -= candidates[i]
+		}
+	}
+
+	fn(candidates, target, 0)
+
+	return paths
+}

leetcode/39.组合总和/combinationSum_test.go

@@ -0,0 +1,38 @@
+package _9_组合总和
+
+import (
+	"reflect"
+	"testing"
+)
+
+func Test_combinationSum(t *testing.T) {
+	type args struct {
+		candidates []int
+		target     int
+	}
+	tests := []struct {
+		name string
+		args args
+		want [][]int
+	}{
+		{name: `输入：candidates = [2,3,6,7], target = 7,
+所求解集为：
+[
+  [7],
+  [2,2,3]
+]`, args: args{
+			candidates: []int{2, 3, 6, 7},
+			target:     7,
+		}, want: [][]int{
+			{2, 2, 3},
+			{7},
+		}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := combinationSum(tt.args.candidates, tt.args.target); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("combinationSum() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

leetcode/40.组合总和II/combinationSum2.go

@@ -0,0 +1,51 @@
+package _0_组合总和II
+
+import "sort"
+
+func combinationSum2(candidates []int, target int) [][]int {
+
+	var (
+		use   = make([]bool, len(candidates))
+		paths [][]int
+		path  []int
+		fn    func(candidates []int, target int, startIdx int)
+		sum   int
+	)
+	sort.Ints(candidates)
+
+	fn = func(candidates []int, target int, startIdx int) {
+		if sum == target {
+			tmp := make([]int, len(path))
+			copy(tmp, path)
+			paths = append(paths, tmp)
+			return
+		}
+
+		if sum > target || startIdx >= len(candidates) {
+			return
+		}
+
+		for i := startIdx; i < len(candidates); i++ {
+			// 判断树层是够被使用 false
+			if i > 0 && candidates[i] == candidates[i-1] && !use[i-1] {
+				continue
+			}
+			/*树支开始*/
+			use[i] = true
+			path = append(path, candidates[i])
+			sum += candidates[i]
+			fn(candidates, target, i+1)
+			/*树支结束*/
+			/*树层开始*/
+			use[i] = false
+			path = path[:len(path)-1]
+			sum -= candidates[i]
+			/*树层结束*/
+		}
+
+	}
+
+	fn(candidates, target, 0)
+
+	return paths
+}

leetcode/40.组合总和II/combinationSum2_test.go

@@ -0,0 +1,43 @@
+package _0_组合总和II
+
+import (
+	"reflect"
+	"testing"
+)
+
+func Test_combinationSum2(t *testing.T) {
+	type args struct {
+		candidates []int
+		target     int
+	}
+	tests := []struct {
+		name string
+		args args
+		want [][]int
+	}{
+		{name: `输入: candidates = [10,1,2,7,6,1,5], target = 8,
+所求解集为:
+[
+  [1, 7],
+  [1, 2, 5],
+  [2, 6],
+  [1, 1, 6]
+]
+`, args: args{
+			candidates: []int{10, 1, 2, 7, 6, 1, 5},
+			target:     8,
+		}, want: [][]int{
+			{1, 7},
+			{1, 2, 5},
+			{2, 6},
+			{1, 1, 6},
+		}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := combinationSum2(tt.args.candidates, tt.args.target); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("combinationSum2() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}