View Compilation Error

0_0_11164852_9711.c:2:16: queue: No such file or directory
0_0_11164852_9711.c:3: error: syntax error before "namespace"
0_0_11164852_9711.c: In function `dfs':
0_0_11164852_9711.c:16: error: `queue' undeclared (first use in this function)
0_0_11164852_9711.c:16: error: (Each undeclared identifier is reported only once
0_0_11164852_9711.c:16: error: for each function it appears in.)
0_0_11164852_9711.c:16: error: `node' undeclared (first use in this function)
0_0_11164852_9711.c:16: error: `q' undeclared (first use in this function)