[LeetCode] Reverse Integer

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <climits>
 4 
 5 using namespace std;
 6 
 7 int Solve(){
 8     int data_in;
 9     cin>>data_in;
10 
11     bool ispositive = data_in>=0?true:false;
12     int data_ret = 0;
13 
14     while(data_in){
15         data_ret *= 10;
16         int add = data_in % 10;
17 
18         if((ispositive&&(INT_MAX -data_ret)>=add) ||
19            (!ispositive&&(INT_MIN -data_ret)<=add))
20             data_ret += add;
21         else return -1;//overflow happens
22 
23         data_in /= 10;
24     }
25 
26     return data_ret;
27 }
28 
29 int main()
30 {
31     freopen("txt.in","r",stdin);
32     freopen("txt.out","w",stdout);
33 
34     int case_num=0;
35     cin>>case_num;
36 
37     for(int i=0;i<case_num;++i){
38         cout<<"Case "<<i+1<<": "<<Solve()<<endl;
39     }
40 
41     return 0;
42 }