#include <stdio.h>
#include "lceb.h"


int eval_node(node, depth, pvals, pops)
    NODE *node;
    int depth;
    int *pvals;
    char *pops;
{
    static int *vals, *val_zero;
    static char *ops, *ops_zero;
    static int ncalc;
    static *node_zero;
    int val1, val2, op, res=-1, i;

    if (depth == 0) {
        val_zero=vals=pvals;
        ops_zero=ops=pops;
        node_zero=node;
        ncalc=0;
    }
#   ifdef  DEBUG1
    for (i=0; i<=depth; ++i)
        printf("  ");
    printf("eval : depth=%d : ", depth);
    if (node->type == TREE_NODE) {
        printf("node(%c)\n", *ops);
    } else {
        printf("val(%d)\n", *vals);
    }
#   endif
    if (node->type == TREE_LEAF) {
        node->val=*vals;
        res=*vals;
        vals++;
    } else {
        op=*ops;
        node->op=*ops;
        ops++;
        ncalc++;
        //printf("NEW node(%s)\n", ops);
        val1=eval_node(node->left, depth+1, pvals, ops);
        if (val1 <= 0)
            return -1;
        val2=eval_node(node->right, depth+1, pvals, ops);
        if (val2 <= 0)
            return -1;
        switch (op) {
            case Add:
                res=val1+val2;
                break;
            case Mul:
                res=val1*val2;
                break;
            case Sub:
                if (val1 > val2)
                    res=val1-val2;
                break;
            case Div:
                if (val1 > val2 && (val1 % val2 == 0))
                    res=val1/val2;
                break;
            case Nop:
            case End:
                fprintf(stderr, "Fatal: bad op [%d] in eval\n", op);
                exit(1);
                break;
        }
    }
    if (res > 0)
        check_best(res, ncalc, node_zero, val_zero, ops_zero);
#   ifdef  DEBUG1
    for (i=0; i<=depth; ++i)
        printf("  ");
    printf("res=%d\n", res);
#   endif
    return res;
}