07.整数反转

 1 class Solution {
 2      
 3      public static int getRev(int x){
 4         int temp =0;
 5         while(x!=0){
 6             temp = temp*10+x%10;
 7             x = x/10;
 8 
 9             // if((Integer.MAX_VALUE-temp)/10<temp){
10             //     temp = 0;
11             //     break;
12             // }
13         }
14          return  temp;
15     }
16 
17     public static int getFu(int x){
18         x= -1*x;
19         return  -1*getRev(x);
20     }
21 
22     
23     public int reverse(int x) {
24         int result =0;
25         if(x>=0){
26             result = getRev(x);
27         }else{
28             result = getFu(x);
29         }
30         return result;
31     }
32 }

 1 class Solution {
 2       
 3     public int reverse(int x) {
 4         int max = 0x7fffffff, min = 0x80000000;//int的最大值最小值
 5     long temp=0;
 6     while(x!=0){
 7         temp=temp*10+x%10;
 8         x/=10;
 9     }
10     
11     if(temp>max||temp<min){
12         return 0;
13     }
14      else{
15         return (int)temp;
16      }
17     }
18 }