Ein wenig Internet-Recherche ergibt:

According to the Retail Theft Barometer, perfume, cosmetics and skincare are the most frequently stolen items and shrinkage costs retailers on average over 1% of their revenue each year. New results from a study conducted by Arthur Andersen Business Consulting at 13 CVS Pharmacy locations in the USA and sponsored by ADT-Sensormatic found that items not source protected were 47% more likely to be stolen than those with protection. The study also revealed that unprotected items were 46% more likely to be out of stock than those source tagged. The report concludes that, "Source tagging reduces theft and contributes directly to improved gross profit for both suppliers and retailers." [Synergy -STC]

Ich habe also genau die Artikel erwischt, die am meisten gestohlen werden.

Ich habe für jeden Knoten eine eigene Behandlungsroutine geschrieben, die Folgende ist beispielsweise für die Behandlung von "add"-Befehlen zuständig. Das gezeigte Prinzip sollte aber für so ziemlich alle binären Operationen anwendbar sein.

83 /*              arithmetics
84 */
85 
86 
87 node_add(treenodep a, treenodep b, treenodep dest) {
88 
89         if((a->regnr!=-1) && (b->regnr!=-1)) {
90 
91                 if(is_work_reg(a->regnr))
92                         dest->regnr=a->regnr;
93                 else
94                 if(is_work_reg(b->regnr))
95                         dest->regnr=b->regnr;
96                 else
97                         dest->regnr=alloc_register();
98 
99                 print_add(a->regnr, b->regnr, dest->regnr);
100 
101         } else
102         if(a->regnr!=-1) {
103 
104                 if(is_work_reg(a->regnr)) {
105 
106                         dest->regnr=a->regnr;
107                         print_add_const(a->regnr, b->num, a->regnr);
108 
109                 } else {
110 
111                         dest->regnr=alloc_register();
112                         print_add_const(a->regnr, b->num, dest->regnr);
113                 }
114 
115         } else
116         if(b->regnr!=-1) {
117 
118 
119                 if(is_work_reg(b->regnr)) {
120 
121                         dest->regnr=b->regnr;
122                         print_add_const(b->regnr, a->num, b->regnr);
123 
124                 } else {
125 
126                         dest->regnr=alloc_register();
127                         print_add_const(b->regnr, a->num, dest->regnr);
128                 }
129 
130         } else {
131 
132                 /* herzlichen Dank an Peter / Informatik-Forum
133                    für diese GENIALE Idee! :-) */
134 
135                 if(((a->num+b->num)>-254) &&
136                    ((a->num+b->num)< 255)) {
137 
138                         dest->num=a->num+b->num;
139                         dest->regnr=-1;
140 
141                 } else {
142 
143                         dest->regnr=alloc_register();
144                         print_store_const(a->num, dest->regnr);
145                         print_add_const(dest->regnr, b->num, dest->regnr);
146 
147                 }
148 
149         }
150 }