View Compilation Error

0_0_30331227_14512.cpp: In function 'int main()':
0_0_30331227_14512.cpp:47:33: error: 'memset' was not declared in this scope
         memset(f, 0x3f, sizeof f);
                                 ^
0_0_30331227_14512.cpp:53:30: error: 'sort' was not declared in this scope
         sort(a + 1, a + 1 + n);
                              ^