View Compilation Error

0_0_30061700_22596.cpp: In function 'void get_sg()':
0_0_30061700_22596.cpp:7:27: error: 'memset' was not declared in this scope
     memset(sg,0,sizeof(sg));
                           ^
0_0_30061700_22596.cpp: In function 'int main()':
0_0_30061700_22596.cpp:28:18: error: 'scanf' was not declared in this scope
     scanf("%d",&T);
                  ^
0_0_30061700_22596.cpp:31:30: error: 'printf' was not declared in this scope
         printf("Case #%d: ",t);
                              ^