/in/foo.c:4:1: error: unknown type name 'using'
 using namespace std;
 ^~~~~
/in/foo.c:4:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'std'
 using namespace std;
                 ^~~
/in/foo.c:3:15: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
 #define MAXN 1<<(10)+1
               ^
/in/foo.c:6:20: note: in expansion of macro 'MAXN'
 int a[150][15],dep[MAXN],visit[MAXN];
                    ^~~~
/in/foo.c:3:15: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
 #define MAXN 1<<(10)+1
               ^
/in/foo.c:6:32: note: in expansion of macro 'MAXN'
 int a[150][15],dep[MAXN],visit[MAXN];
                                ^~~~
/in/foo.c: In function 'spfa':
/in/foo.c:11:5: error: 'queue' undeclared (first use in this function)
     queue<int>Q;
     ^~~~~
/in/foo.c:11:5: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:11:11: error: expected expression before 'int'
     queue<int>Q;
           ^~~
/in/foo.c:12:5: error: 'Q' undeclared (first use in this function)
     Q.push(src);
     ^