View Compilation Error

0_0_24423892_28558.cpp: In function 'int lenn(char*)':
0_0_24423892_28558.cpp:32:22: error: 'max' was not declared in this scope
         ans=max(ans,t);
                      ^
0_0_24423892_28558.cpp: In function 'void IDAstar(int, char*, int)':
0_0_24423892_28558.cpp:45:37: error: 'memcpy' was not declared in this scope
         memcpy(tmp,a,60*sizeof(char));
                                     ^
0_0_24423892_28558.cpp: In function 'int main()':
0_0_24423892_28558.cpp:56:18: error: 'scanf' was not declared in this scope
     scanf("%d",&k);
                  ^
0_0_24423892_28558.cpp:71:34: error: 'printf' was not declared in this scope
                 printf("%d\n",sum);
                                  ^
0_0_24423892_28558.cpp:80:26: error: 'printf' was not declared in this scope
             printf("-1\n");
                          ^