[LeetCode] Reverse Integer
Reverse digits of an integer.
Example1: x = 123, return 321
Example2: x = -123, return -321
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 }
txt.in
9
89
89000
00789
1000000003
0
000
-789
-789000
-0
txt.out
Case 1: 98
Case 2: 98
Case 3: 987
Case 4: -1
Case 5: 0
Case 6: 0
Case 7: -987
Case 8: -987
Case 9: 0
