zone01-Piscine/atoi.go at master · kinoz01/zone01-Piscine · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
package main

import "fmt"

func main() {
	fmt.Println(Atoi("12345"))
	fmt.Println(Atoi("0000000012345"))
	fmt.Println(Atoi("012 345"))
	fmt.Println(Atoi("Hello World!"))
	fmt.Println(Atoi("+1234"))
	fmt.Println(Atoi("-1234"))
	fmt.Println(Atoi("++1234"))
	fmt.Println(Atoi("--1234"))
}

func Atoi(s string) int {
	var n int
	sliceS := []rune(s)
	first := true
	for i := 0; i < len(sliceS); i++ {
		if (sliceS[0] == '-' || sliceS[0] == '+') && first {
			first = false
			continue
		}
		if sliceS[i] > '9' || sliceS[i] < '0' {
			return 0
		}
		n = n*10 + int(sliceS[i]-'0')
	}
	if sliceS[0] == '-' {
		return -n
	}
	return n
}

// quest 3 / checkpoint