View Compilation Error

0_0_13508838_1751.cpp: In function 'int main()':
0_0_13508838_1751.cpp:10:23: error: 'strlen' was not declared in this scope
         int l=strlen(a);sum=0;
                       ^
0_0_13508838_1751.cpp:24:10: error: 'i' was not declared in this scope
          i=0;
          ^
0_0_13508838_1751.cpp:48:17: error: 'ii' was not declared in this scope
             for(ii=1;ii<=7-i;ii++)cout<<" ";
                 ^