View Compilation Error

0_0_23613707_29952.cpp: In function 'int f(int, int)':
0_0_23613707_29952.cpp:12:25: error: 'memset' was not declared in this scope
     memset(v,0,sizeof(v));
                         ^
0_0_23613707_29952.cpp: In function 'int main()':
0_0_23613707_29952.cpp:34:36: error: 'memset' was not declared in this scope
             memset(sg,-1,sizeof(sg));
                                    ^