Leetcode7--->reverse integer (Reversed integer)

Title: Given an integer, the value after which the integer is reversed;

Example:

EXAMPLE1:X = 123, return 321
example2:x = -123, return-321

Problem Solving Ideas:

Here are just a few points to note:

1. If the integer is a negative number,-123, then the reversal is 321, so it is necessary to reverse from the first position instead of the No. 0 position;

2. If the integer For example: 12300, then the reversal is 321, instead of 00321, so after reversal, need to remove the preceding 0;

3. If the integer example is 2147483647, then the reversal is 7463847412 > Integer.max_value, then 0 is returned;

1  Public classSolution {2      Public intReverseintx) {3         Char[] ch =string.valueof (x). ToCharArray ();4         intBegin = 0;5         intFlag = 0;//flag is used to indicate positive or negative numbers .6         intEnd = Ch.length-1;7         if(x < 0) {//Negative number8Flag = 1;9         }TenBegin =Flag; One          while(Begin <end) { A Exchange (CH, begin, end); -Begin + +; -End--; the         } -StringBuffer SB =NewStringBuffer (); -         inti =Flag;
Minus 0 in front of the reversal. -          for(; i < ch.length; i++){ +             if(Ch[i]! = ' 0 ') -                  Break; +         } A         if(Flag = = 1) atSb.append ("-"); -Sb.append (CH, I, ch.length-i); -         if(Sb.tostring (). Equals ("")) -             return0; -         Doubleres =double.valueof (sb.tostring ()); -         if(Res > Integer.max_value | | Res <integer.min_value) in             return0; -         returninteger.valueof (sb.tostring ()); to          +          -     } the      Public voidExchangeChar[] ch,intIndex1,intindex2) { *         Charc =Ch[index1]; $CH[INDEX1] =Ch[index2];Panax NotoginsengCH[INDEX2] =C; -     } the}

Leetcode7--->reverse integer (Reversed integer)