c-gcc, 99 bytes

Result

AC

Duration

1117ms

Code [DL]

i,w;main(h){scanf("%d%d",&h,&w);for(i=++w*h;i--;)putchar(i%w<w-1&i%w>1&i/w<h-1&&i/w?32:i%w?42:10);}

stdin

78
48

stdout

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stderr

/tmp/code.c:1:1: warning: data definition has no type or storage class
 i,w;main(h){scanf("%d%d",&h,&w);for(i=++w*h;i--;)putchar(i%w<w-1&i%w>1&i/w<h-1&&i/w?32:i%w?42:10);}
 ^
/tmp/code.c:1:1: warning: type defaults to 'int' in declaration of 'i' [-Wimplicit-int]
/tmp/code.c:1:3: warning: type defaults to 'int' in declaration of 'w' [-Wimplicit-int]
 i,w;main(h){scanf("%d%d",&h,&w);for(i=++w*h;i--;)putchar(i%w<w-1&i%w>1&i/w<h-1&&i/w?32:i%w?42:10);}
   ^
/tmp/code.c:1:5: warning: return type defaults to 'int' [-Wimplicit-int]
 i,w;main(h){scanf("%d%d",&h,&w);for(i=++w*h;i--;)putchar(i%w<w-1&i%w>1&i/w<h-1&&i/w?32:i%w?42:10);}
     ^~~~
/tmp/code.c: In function 'main':
/tmp/code.c:1:5: warning: type of 'h' defaults to 'int' [-Wimplicit-int]
/tmp/code.c:1:13: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
 i,w;main(h){scanf("%d%d",&h,&w);for(i=++w*h;i--;)putchar(i%w<w-1&i%w>1&i/w<h-1&&i/w?32:i%w?42:10);}
             ^~~~~
/tmp/code.c:1:13: warning: incompatible implicit declaration of built-in function 'scanf'
/tmp/code.c:1:13: note: include '<stdio.h>' or provide a declaration of 'scanf'
+#include <stdio.h>
 i,w;main(h){scanf("%d%d",&h,&w);for(i=++w*h;i--;)putchar(i%w<w-1&i%w>1&i/w<h-1&&i/w?32:i%w?42:10);}
             ^~~~~
/tmp/code.c:1:50: warning: implicit declaration of function 'putchar' [-Wimplicit-function-declaration]
 i,w;main(h){scanf("%d%d",&h,&w);for(i=++w*h;i--;)putchar(i%w<w-1&i%w>1&i/w<h-1&&i/w?32:i%w?42:10);}
                                                  ^~~~~~~
/tmp/code.c:1:61: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
 i,w;main(h){scanf("%d%d",&h,&w);for(i=++w*h;i--;)putchar(i%w<w-1&i%w>1&i/w<h-1&&i/w?32:i%w?42:10);}
                                                          ~~~^~~~
/tmp/code.c:1:75: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
 i,w;main(h){scanf("%d%d",&h,&w);for(i=++w*h;i--;)putchar(i%w<w-1&i%w>1&i/w<h-1&&i/w?32:i%w?42:10);}
                                                                        ~~~^~~~