View Compilation Error

0_0_33505021_10982.cpp: In function 'void bfs(int)':
0_0_33505021_10982.cpp:18:31: error: 'memset' was not declared in this scope
     memset(pre, 0, sizeof(pre));
                               ^
0_0_33505021_10982.cpp: In function 'long long int KM()':
0_0_33505021_10982.cpp:44:29: error: 'memset' was not declared in this scope
     memset(lx, 0, sizeof(lx));
                             ^
0_0_33505021_10982.cpp: In function 'int main()':
0_0_33505021_10982.cpp:59:19: error: 'scanf' was not declared in this scope
     scanf("%d", &T);
                   ^
0_0_33505021_10982.cpp:68:46: error: 'printf' was not declared in this scope
         printf("Case #%d: %I64d\n", _i, -KM());
                                              ^