View Compilation Error

0_0_13772521_18582.cpp: In function 'bool cmp(const Student&, const Student&)':
0_0_13772521_18582.cpp:20:31: error: 'strcmp' was not declared in this scope
   return (strcmp(a.name,b.name)<0);
                               ^
0_0_13772521_18582.cpp: In function 'int main()':
0_0_13772521_18582.cpp:28:29: error: 'memset' was not declared in this scope
   memset(data,0,sizeof(data));//memeset()函数对数组进行清零！！！
                             ^
0_0_13772521_18582.cpp:52:29: error: 'dat' was not declared in this scope
       cout<<left<<setw(10)<<dat
                             ^
0_0_13772521_18582.cpp:52:29: error: expected '}' at end of input