View Compilation Error

0_0_39681717_15719.c:2:1: error: unknown type name 'using'
    2 | using namespace std;
      | ^~~~~
0_0_39681717_15719.c:2:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'std'
    2 | using namespace std;
      |                 ^~~
0_0_39681717_15719.c:10:1: error: unknown type name 'bool'
   10 | bool flag[200000];
      | ^~~~
0_0_39681717_15719.c:2:1: note: 'bool' is defined in header '<stdbool.h>'; did you forget to '#include <stdbool.h>'?
    1 | #include<stdio.h>
  +++ |+#include <stdbool.h>
    2 | using namespace std;