/**
 * @Author :田宇寒.
 * @Date :Created in 10:46 2021年6月3日
 * @Description: 字符串转整数
 * @Source:力扣(LeetCode) 链接:https://leetcode-cn.com/problems/string-to-integer-atoi 著作权归领扣网络所有。商业转载请联系官方授权,非商业转载请注明出处。
 * @Modified By:
 * @Version: 1.0
 */
public class code8 {

 public static void main(String[] args) {
 Solution solution = new Solution();
 System.out.println(solution.myAtoi("2147483646"));
 System.out.println(solution.myAtoi("-91283472332"));
 System.out.println(solution.myAtoi("-42"));
 }

 static class Solution {
 public int myAtoi(String s) {
 char[] chars = s.trim().toCharArray();
 if (chars.length == 0) {
 return 0;
 }
 int sign = 1;
 int i = 0;
 if (!Character.isDigit(chars[0])) {
 if (chars[0] == '-') {
 sign = -1;
 } else if (chars[0] == '+') {
 sign = 1;
 } else {
 return 0;
 }
 i++;
 }
 long result = 0;
 while (i < chars.length && Character.isDigit(chars[i])) {
 switch (sign) {
 case 1: result = Math.min(result*10+chars[i] - '0',Integer.MAX_VALUE);break;
 case -1: result = Math.max(result*10+(chars[i] - '0')*sign, Integer.MIN_VALUE);break;
 default: return 0;
 }
 i++;
 }
 return (int) result;
 }
 }
}