View Compilation Error

0_0_32865256_4469.cpp: In function 'void max_flow()':
0_0_32865256_4469.cpp:24:37: error: 'memset' was not declared in this scope
         memset(visit,0,sizeof(visit));
                                     ^
0_0_32865256_4469.cpp: In function 'int main()':
0_0_32865256_4469.cpp:72:29: error: 'memset' was not declared in this scope
         memset(f,0,sizeof(f));
                             ^