Reverse Integer
Reverse digits of an integer.
Example1: x = 123, return 321
Example2: x = -123, return -321
注意考虑几个情况，x=1534236460 1534236469 -2147483647等等。
写的代码有点冗长了。
1 public class Solution { 2 public int reverse(int x) { 3 7 8 if(x<0){//负数 9 10 long xx = x; 11 xx=xx*(-1); 12 if(xx>Integer.MAX_VALUE){ 13 // System.out.println("///////"); 14 return 0; 15 } 16 17 Integer num = new Integer(x); 18 num=-num; 19 String s = num.toString(); 20 StringBuilder sb = new StringBuilder(s); 21 sb.reverse(); 22 String ss = sb.toString(); 23 24 if(Long.parseLong(ss)>Integer.MAX_VALUE){ 25 // System.out.println("///////"); 26 return 0; 27 } 28 int i = -Integer.parseInt(ss); 29 return i; 30 } 31 32 else{//正数 35 Integer num = new Integer(x); 36 String s = num.toString(); 37 StringBuilder sb = new StringBuilder(s); 38 sb.reverse(); 39 String ss = sb.toString(); 40 41 42 if(Long.parseLong(ss)>Integer.MAX_VALUE){ 43 // System.out.println("///////"); 44 return 0; 45 } 46 48 return Integer.parseInt(ss); 49 } 50 51 } 52 53 }
312 ms.
