View Compilation Error

0_0_17600174_32498.cpp: In function 'void init()':
0_0_17600174_32498.cpp:19:26: error: 'menset' was not declared in this scope
  menset(num,0,sizeof(num));
                          ^
0_0_17600174_32498.cpp: In function 'int main()':
0_0_17600174_32498.cpp:42:27: error: 'memset' was not declared in this scope
   memset(num,0,sizeof(num));
                           ^
0_0_17600174_32498.cpp:63:20: error: too few arguments to function 'long long int haha(long long int, long long int)'
    cout << haha(sum) <<endl;
                    ^
0_0_17600174_32498.cpp:13:4: note: declared here
 ll haha(ll n,ll sum){
    ^