View Compilation Error

0_0_22048954_28685.c:2:1: error: expected identifier or '(' before '/' token
 //using namespace std;
 ^
0_0_22048954_28685.c:4:5: error: variably modified 'f' at file scope
 int f[N][M][2];
     ^
0_0_22048954_28685.c:4:5: error: variably modified 'f' at file scope
0_0_22048954_28685.c:5:5: error: variably modified 'sum' at file scope
 int sum[N];
     ^
0_0_22048954_28685.c: In function 'main':
0_0_22048954_28685.c:22:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for(int i = 1; i <= n; ++i)
   ^
0_0_22048954_28685.c:22:3: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_22048954_28685.c:54:3: error: expected expression before '/' token
   //  cerr << cnt << endl;
   ^