View Compilation Error

0_0_34092927_2605.cpp: In function 'int main()':
0_0_34092927_2605.cpp:7:22: error: 'memset' was not declared in this scope
  memset(b,0,sizeof(b));
                      ^
0_0_34092927_2605.cpp:10:21: error: 'strlen' was not declared in this scope
   int i,len=strlen(a);
                     ^
0_0_34092927_2605.cpp:29:12: error: 'k' was not declared in this scope
       if(j<k)
            ^
0_0_34092927_2605.cpp:34:11: error: 'k' was not declared in this scope
      if(j<k)
           ^