From cf0c5b94dff44b961b924a5f5bc1a228fbf3b8e4 Mon Sep 17 00:00:00 2001
From: guowenfeng <841784596@qq.com>
Date: Mon, 7 Jun 2021 21:53:02 +0800
Subject: [PATCH] dfs
---
.idea/workspace.xml | 26 ++++++----
.../main.go" | 50 +++++++++++++++++++
main.go | 40 +++++++++------
3 files changed, 91 insertions(+), 25 deletions(-)
create mode 100644 "leet_code/494.\347\233\256\346\240\207\345\222\214/main.go"
diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index 84e9488..330d9a7 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -63,13 +63,13 @@
-
-
+
+
-
-
+
+
@@ -108,11 +108,11 @@
+
@@ -124,11 +124,19 @@
true
+
+
+
+ file://$PROJECT_DIR$/leet_code/494.目标和/main.go
+ 37
+
+
+
+
-
-
-
+
+
diff --git "a/leet_code/494.\347\233\256\346\240\207\345\222\214/main.go" "b/leet_code/494.\347\233\256\346\240\207\345\222\214/main.go"
new file mode 100644
index 0000000..fc76e57
--- /dev/null
+++ "b/leet_code/494.\347\233\256\346\240\207\345\222\214/main.go"
@@ -0,0 +1,50 @@
+package main
+
+import "fmt"
+
+func findTargetSumWays(nums []int, target int) int {
+ res := 0
+
+ //dfs(curSum, target, index, &res, nums, '+')
+ //dfs(curSum, target, index, &res, nums, '-')
+
+ dfsBetter(nums, target, 0, 0, &res)
+
+ return res
+}
+
+func dfsBetter(nums []int, target, sum, index int, res *int) {
+ if index == len(nums) {
+ if sum == target {
+ *res++
+ }
+ } else {
+ dfsBetter(nums, target, sum + nums[index], index + 1, res)
+ dfsBetter(nums, target, sum - nums[index], index + 1, res)
+ }
+}
+
+func dfs(curSum, target, index int, res *int, nums []int, op byte) {
+ if op == '+' {
+ curSum += nums[index]
+ } else {
+ curSum -= nums[index]
+ }
+ index++
+
+ if curSum == target && index == len(nums){
+ *res += 1
+ return
+ } else if index == len(nums) {
+ return
+ } else {
+ dfs(curSum, target, index, res, nums, '+')
+ dfs(curSum, target, index, res, nums, '-')
+ }
+}
+
+
+
+func main() {
+ fmt.Println(findTargetSumWays([]int{1, 1, 1, 1, 1}, 3))
+}
diff --git a/main.go b/main.go
index 8547797..2f97923 100644
--- a/main.go
+++ b/main.go
@@ -2,28 +2,36 @@ package main
import (
"fmt"
- "reflect"
+ "os"
+ "time"
)
func main() {
- chan1 := make(chan int, 1)
- chan2 := make(chan string, 2)
- chan3 := make(chan float64, 1)
+ defer fmt.Println("defer main")
+ var user = os.Getenv("USER_")
- // 异步监听
go func() {
- for {
- // select 会等待某个管道就绪，若同时多个就绪，会随机选一个处理
- select {
- case params := <- chan1:
- fmt.Println(params)
- case <- chan2:
- case <- chan3:
- default:
- // do nothing
+ defer func() {
+ fmt.Println("defer caller")
+ if err := recover(); err != nil {
+ fmt.Println("recover success. err: ", err)
}
- }
+ }()
+
+ func() {
+ defer func() {
+ fmt.Println("defer here")
+ }()
+
+ if user == "" {
+ panic("should set user env.")
+ }
+
+ // 此处不会执行
+ fmt.Println("after panic")
+ }()
}()
- reflect.SliceHeader{}
+ time.Sleep(100)
+ fmt.Println("end of main function")
}