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86 lines
1.8 KiB
C
86 lines
1.8 KiB
C
/* j/3/can.c
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**
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** This file is in the public domain.
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*/
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#include "all.h"
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/* functions
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*/
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u3_noun
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u3qc_can(u3_atom a,
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u3_noun b)
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{
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if ( !_(u3a_is_cat(a)) || (a >= 32) ) {
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return u3m_bail(c3__fail);
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}
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else {
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c3_g a_g = a;
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c3_w tot_w = 0;
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c3_w* sal_w;
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/* Measure and validate the slab required.
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*/
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{
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u3_noun cab = b;
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while ( 1 ) {
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u3_noun i_cab, pi_cab, qi_cab;
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if ( 0 == cab ) {
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break;
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}
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if ( c3n == u3du(cab) ) return u3m_bail(c3__fail);
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i_cab = u3h(cab);
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if ( c3n == u3du(i_cab) ) return u3m_bail(c3__fail);
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pi_cab = u3h(i_cab);
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qi_cab = u3t(i_cab);
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if ( c3n == u3a_is_cat(pi_cab) ) return u3m_bail(c3__fail);
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if ( c3n == u3ud(qi_cab) ) return u3m_bail(c3__fail);
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if ( (tot_w + pi_cab) < tot_w ) return u3m_bail(c3__fail);
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tot_w += pi_cab;
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cab = u3t(cab);
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}
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if ( 0 == tot_w ) {
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return 0;
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}
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if ( 0 == (sal_w = u3a_slaq(a_g, tot_w)) ) {
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return u3m_bail(c3__fail);
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}
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}
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/* Chop the list atoms in.
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*/
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{
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u3_noun cab = b;
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c3_w pos_w = 0;
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while ( 0 != cab ) {
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u3_noun i_cab = u3h(cab);
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u3_atom pi_cab = u3h(i_cab);
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u3_atom qi_cab = u3t(i_cab);
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u3r_chop(a_g, 0, pi_cab, pos_w, sal_w, qi_cab);
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pos_w += pi_cab;
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cab = u3t(cab);
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}
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}
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return u3a_malt(sal_w);
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}
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}
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u3_noun
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u3wc_can(u3_noun cor)
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{
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u3_noun a, b;
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if ( (c3n == u3r_mean(cor, u3x_sam_2, &a, u3x_sam_3, &b, 0)) ||
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(c3n == u3ud(a)) )
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{
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return u3m_bail(c3__fail);
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} else {
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return u3qc_can(a, b);
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}
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}
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