View Compilation Error

0_0_14543489_9836.cpp: In function 'int prim()':
0_0_14543489_9836.cpp:7:25: error: 'memset' was not declared in this scope
     memset(c,0,sizeof(c));
                         ^
0_0_14543489_9836.cpp: In function 'int main()':
0_0_14543489_9836.cpp:47:18: error: 'scanf' was not declared in this scope
     scanf("%d",&t);
                  ^
0_0_14543489_9836.cpp:89:28: error: 'printf' was not declared in this scope
        printf("%d\n",prim());
                            ^