/in/foo.c: In function 'Output':
/in/foo.c:4:4: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
    for(int i=0;i<n;i++) 
    ^~~
/in/foo.c:6:8: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
        printf("\n");
        ^~~~~~
/in/foo.c: In function 'main':
/in/foo.c:14:19: error: 'i' undeclared (first use in this function)
     scanf("%d",&a[i]);
                   ^
/in/foo.c:14:19: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:15:2: warning: implicit declaration of function 'output' [-Wimplicit-function-declaration]
  output(a,n);
  ^~~~~~