题解 | #将字符串转化为整数#

 package main

/**
  * 
  * @param str string字符串 
  * @return int整型
*/
func atoi( str string ) int {
   
    c := 0
    flag := 1
    for i, _ := range str {
        if str[i] >= '0' &&  str[i] <= '9' {
            n := int(str[i] - '0')
            c = c * 10 + n
        } else if str[i] == '+' ||   str[i] == ' '{
            continue
        } else if str[i] == '-' {
            flag = -1
        } else {
            return flag*c
        }
    }
    return flag*c
}