/in/foo.c: In function 'main':
/in/foo.c:6:1: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
 scanf("%d %d",&n1,&n2);
 ^~~~~
/in/foo.c:6:1: warning: incompatible implicit declaration of built-in function 'scanf'
/in/foo.c:6:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
/in/foo.c:12:1: warning: implicit declaration of function 'FindMaxs' [-Wimplicit-function-declaration]
 FindMaxs(a,n1);
 ^~~~~~~~
/in/foo.c: At top level:
/in/foo.c:19:6: warning: conflicting types for 'FindMaxs'
 void FindMaxs(int a[],int n)
      ^~~~~~~~
/in/foo.c:12:1: note: previous implicit declaration of 'FindMaxs' was here
 FindMaxs(a,n1);
 ^~~~~~~~
/in/foo.c: In function 'FindMaxs':
/in/foo.c:23:1: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
 printf("%d ",a[0]);
 ^~~~~~
/in/foo.c:23:1: warning: incompatible implicit declaration of built-in function 'printf'
/in/foo.c:23:1: note: include '<stdio.h>' or provide a declaration of 'printf'
/in/foo.c:27:5: warning: incompatible implicit declaration of built-in function 'printf'
     printf("%d ",a[i]);
     ^~~~~~
/in/foo.c:27:5: note: include '<stdio.h>' or provide a declaration of 'printf'
/in/foo.c:29:1: warning: incompatible implicit declaration of built-in function 'printf'
 printf("%d ",a[n-1]);
 ^~~~~~
/in/foo.c:29:1: note: include '<stdio.h>' or provide a declaration of 'printf'
/in/foo.c:21:7: warning: unused variable 'k' [-Wunused-variable]
 int i,k;
       ^