Files
Le-Compte-est-Bon/eval.c

138 lines
3.7 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include "lceb.h"
static int nodes_calc; /* total nodes evaluated */
static int leaves_calc; /* total leaves evaluated */
int firstonly=0;
int eval_node(node, depth, pvals, pops, ncalcs)
NODE *node;
int depth;
int *pvals;
char *pops;
int *ncalcs;
{
static int *vals, *val_zero;
static char *ops, *ops_zero;
static int totcalc;
int val1, val2, op, res=-1, lcalcs, rcalcs, diff;
if (depth == 0) {
val_zero=vals=pvals;
ops_zero=ops=pops;
totcalc=0;
}
# ifdef DEBUG_EVAL
for (i=0; i<=depth; ++i)
printf(" ");
printf("eval : depth=%d : ncalcs=%d ", depth, *ncalcs);
if (node->type == TREE_NODE) {
printf("node(%c)\n", *ops);
print_node(node, TREE_TOP, 0, 0);
} else {
printf("leaf(%d)\n", *vals);
}
# endif
if (node->type == TREE_LEAF) {
leaves_calc++;
node->val=*vals;
res=*vals;
vals++;
*ncalcs=0;
//printf("leaf=%d\n", res);
} else {
nodes_calc++;
op=*ops;
node->op=*ops;
ops++;
totcalc++;
val1=eval_node(node->left, depth+1, pvals, ops, &lcalcs);
if (val1 <= 0)
return val1;
val2=eval_node(node->right, depth+1, pvals, ops, &rcalcs);
if (val2 <= 0)
return val2;
switch (op) {
case Add:
res=val1+val2;
break;
case Mul:
if (val1 > 1 && val2 > 1) /* we avoid "x*1" */
res=val1*val2;
break;
case Sub:
if (val1<val2) {
NODE *tmp=node->left;
# ifdef DEBUG_EVAL2
printf("eval: Sub: swapping val1=%d val2=%d\n", val1, val2);
# endif
node->left=node->right;
node->right=tmp;
}
if (val1 != val2) {
res=val1-val2;
}
if (res == val2) /* already found in subtree */
res=-1;
break;
case Div:
if (val1<val2) {
NODE *tmp=node->left;
# ifdef DEBUG_EVAL2
printf("eval: Div: swapping val1=%d val2=%d\n", val1, val2);
# endif
node->left=node->right;
node->right=tmp;
}
if (val2 != 1 && (val1 % val2 == 0))
res=val1/val2;
if (res == val2) /* already found in subtree */
res=-1;
break;
case Nop:
case End:
fprintf(stderr, "Fatal: bad op [%d] in eval\n", op);
exit(1);
break;
}
*ncalcs=lcalcs+rcalcs+1;
}
if (res > 0) {
diff=check_best(res, *ncalcs, node, val_zero, ops_zero);
//printf("eval=%d firstonly=%d\n", eval, firstonly);
if (diff == 0) { /* exact result, we stop here */
# ifdef DEBUG_EVAL3
printf("EXACT eval=%d\n", diff);
# endif
if (firstonly) {
print_results();
exit(0);
}
res=0;
}
}
if (sigint_received) {
print_results();
exit(1);
}
# ifdef DEBUG_EVAL
for (i=0; i<=depth; ++i)
printf(" ");
printf("res=%d\n", res);
# endif
return res;
}
int get_totnodes()
{
return nodes_calc;
}
int get_totleaves()
{
return leaves_calc;
}