01 //lazy.c  -- Short cut evaluation (Lazy evaluation)
   02 //@CopyLeft by tsaiwn@csie.nctu.edu.tw
   03 #include <stdio.h>
   04 int count = 0;
   05 int gg( ) {
   06    static int y = 36;
   07    printf(" gg will return %d at %d\n", y, ++count);
   08    return y++;
   09 }
   10 int main( ) {
   11    if( gg( ) >= 38  &&  (gg( )%2 !=0) ) printf("Hahaha\n");else printf("ggyy\n");
   12    printf("---\n");
   13    if( gg( ) >= 38  &&  (gg( )%2 !=0) ) printf("Hahaha\n"); else printf("ggyy\n");
   14    printf("--- ---\n");
   15    if( gg( ) >= 38  &&  (gg( )%2 !=0) ) printf("Hahaha\n"); else printf("ggyy\n");
   16    printf("--- --- ---\n");
   17    if( gg( ) >= 38  &&  (gg( )%2 !=0) ) printf("Hahaha\n"); else printf("ggyy\n");
   18    printf("=== ===\n");
   19    if(  (gg( )%2 !=0) && gg( ) >= 38  ) printf("Hahaha\n"); else printf("ggyy\n");
   20    printf("--- --- --- ---\n");
   21    if(  (gg( )%2 !=0) && gg( ) >= 38  ) printf("Hahaha\n"); else printf("ggyy\n");
   22    printf("--- --- --- --- ---\n");
   23    if(  (gg( )%2 !=0) && gg( ) >= 38  ) printf("Hahaha\n"); else printf("ggyy\n");
   24    printf("=== ===\n"); printf("gg ====== %d\n", gg( ) ); printf("=== --- ===\n");
   25    if(  (gg( )%2 !=0) && gg( ) >= 38  ) printf("Hahaha\n"); else printf("ggyy\n");
   26    printf("=== === ===\n");
   27    if(  (gg( )%2 !=0) && gg( ) >= 38  ) printf("Hahaha\n"); else printf("ggyy\n");
   28    if( 49 > 38 && gg( ) >= 38)printf("HeeHee\n"); else printf("Hey\n");
   29    if( 23 > 38 && gg( ) >= 38)printf("HeeHee\n"); else printf("Hey\n");
   30    if( 49 > 38 || gg( ) >= 38)printf("HeeHee\n"); else printf("Hey\n");
   31    printf(" count = %d\n", count);
   32    printf("Hit ENTER key..."); getchar( );
   33    return 0;
   34 }  /******************************************
   35  gg will return 36 at 1
   36 ggyy
   37 ---
   38  gg will return 37 at 2
   39 ggyy
   40 --- ---
   41  gg will return 38 at 3
   42  gg will return 39 at 4
   43 Hahaha
   44 --- --- ---
   45  gg will return 40 at 5
   46  gg will return 41 at 6
   47 Hahaha
   48 === ===
   49  gg will return 42 at 7
   50 ggyy
   51 --- --- --- ---
   52  gg will return 43 at 8
   53  gg will return 44 at 9
   54 Hahaha
   55 --- --- --- --- ---
   56  gg will return 45 at 10
   57  gg will return 46 at 11
   58 Hahaha
   59 === ===
   60  gg will return 47 at 12
   61 gg ====== 47
   62 === --- ===
   63  gg will return 48 at 13
   64 ggyy
   65 === === ===
   66  gg will return 49 at 14
   67  gg will return 50 at 15
   68 Hahaha
   69  gg will return 51 at 16
   70 HeeHee
   71 Hey
   72 HeeHee
   73  count = 16
   74 Hit ENTER key...
   75 ******************************************************/