View Compilation Error

0_0_33025691_29598.cpp: In function 'int main()':
0_0_33025691_29598.cpp:8:26: error: 'memset' was not declared in this scope
   memset(a,'\0',sizeof(a));
                          ^
0_0_33025691_29598.cpp:10:17: error: 'strlen' was not declared in this scope
   for(i=strlen(a)-1;i>=0;i--){
                 ^
0_0_33025691_29598.cpp:13:19: error: 'strlen' was not declared in this scope
   x=pow(2,strlen(a)-1-i);
                   ^