View Compilation Error

0_0_36688293_18634.c:1:1: error: expected identifier or '(' before '/' token
 //#pragma G++ optimize("Ofast")
 ^
0_0_36688293_18634.c:1:3: error: stray '#' in program
 //#pragma G++ optimize("Ofast")
   ^
0_0_36688293_18634.c:4:24: fatal error: bits/stdc++.h: No such file or directory
 #include<bits/stdc++.h>
                        ^
compilation terminated.