View Compilation Error

0_0_22285074_2434.cpp: In function 'void add(char*, char*)':
0_0_22285074_2434.cpp:8:23: error: 'strlen' was not declared in this scope
    int len_a =strlen(a);
                       ^
0_0_22285074_2434.cpp:26:9: error: incompatible types in assignment of 'int' to 'char [1010]'
      sum=temp+48;
         ^
0_0_22285074_2434.cpp:32:14: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
     if (sum!=' ')cout<<sum;
              ^
0_0_22285074_2434.cpp: At global scope:
0_0_22285074_2434.cpp:37:11: error: '::main' must return 'int'
 void main()
           ^
0_0_22285074_2434.cpp: In function 'int main()':
0_0_22285074_2434.cpp:48:27: error: 'strlen' was not declared in this scope
        int len_a =strlen(a);
                           ^
0_0_22285074_2434.cpp:58:5: error: expected '}' at end of input
     }
     ^