將給定的string數(shù)字轉(zhuǎn)換為int
package reed.flyingreed.algo
import com.google.gson.annotations.Until
/**
* Created by thinkreed on 2017/6/28.
*/
fun myatoi(str: String): Int {
if (str.isEmpty()) return 0
//去除頭尾的空格
val tmp = str.trim()
var result = 0
var sign = 1
//判斷正負(fù)號
if ((tmp[0] == '-') or (tmp[0] == '+')) {
sign = if (tmp[0] == '+') 1 else -1
}
for (i in 1 until tmp.length) {
val cur = tmp[i] - '0'
//字符串不是數(shù)字
if ((cur < 0) or (cur > 9)) {
break
}
//判斷溢出
if ((result > Int.MAX_VALUE / 10) or ((result == Int.MAX_VALUE / 10) && (cur > Int.MAX_VALUE % 10))) {
return if (sign == 1) Int.MAX_VALUE else Int.MIN_VALUE
}
result = result * 10 + cur
}
return sign * result
}
