View Compilation Error

0_0_25411348_4826.cpp: In function 'int main()':
0_0_25411348_4826.cpp:50:30: error: 'num1' was not declared in this scope
         printf("%s + %s = ", num1, num2);
                              ^
0_0_25411348_4826.cpp:50:36: error: 'num2' was not declared in this scope
         printf("%s + %s = ", num1, num2);
                                    ^
0_0_25411348_4826.cpp:51:14: error: 'i' was not declared in this scope
         for (i = len-1; i >= 0; i--)
              ^
0_0_25411348_4826.cpp:51:18: error: 'len' was not declared in this scope
         for (i = len-1; i >= 0; i--)
                  ^
0_0_25411348_4826.cpp:54:15: error: 'p' was not declared in this scope
         if(j!=p-1)
               ^