함수 - Part4

#lecture #go

1. Closure

package main

import "fmt"

func main() {
    var x int
    fmt.Println(x) // "0"

    {
        y := 42
        fmt.Println(y) // "42"
        fmt.Println(x) // "0"
    }
    // fmt.Println(y) // not defined y
}

package main

import "fmt"

func main() {
    a := incrementor()
    b := incrementor()

    fmt.Println(a()) // "1"
    fmt.Println(a()) // "2"
    fmt.Println(a()) // "3"
    fmt.Println(b()) // "1"
    fmt.Println(b()) // "2"
}

func incrementor() func() int {
    var x int
    return func() int {
        x++
        return x
    }
}

2. 재귀

전통적인 2d 길찾기 문제 with recursive func in go!

package main

import "fmt"

var n = 4
var m = 5

var board = [4][5]int{
    [5]int{0, 0, 0, 0, 0},
    [5]int{1, 1, 1, 1, 0},
    [5]int{1, 1, 0, 1, 0},
    [5]int{1, 1, 0, 0, 0},
}
var visited = [4][5]bool{}

func main() {
    dfs(0, 0)
}

var dy = [4]int{0, 0, 1, -1}
var dx = [4]int{1, -1, 0, 0}

func dfs(r int, c int) {
    visited[r][c] = true
    fmt.Printf("r : %v, c : %v \n", r, c)
    for d := 0; d < 4; d++ {
        ty, tx := r+dy[d], c+dx[d]
        if isValid(ty, tx) && !visited[ty][tx] {
            visited[ty][tx] = true
            dfs(ty, tx)
        }
    }
}

func isValid(r int, c int) bool {
    return r >= 0 && r < n && c >= 0 && c < m
}

실행 결과

r : 0, c : 0 
r : 1, c : 0 
r : 1, c : 1 
r : 1, c : 2 
r : 1, c : 3 
r : 2, c : 3 
r : 2, c : 1 
r : 2, c : 0 
r : 3, c : 0 
r : 3, c : 1

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Last update: May 29, 2023
Created: May 29, 2023