mirror of https://gitlab.com/QEF/q-e.git
64 lines
1.2 KiB
C
64 lines
1.2 KiB
C
/*
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Copyright (C) 2002 FPMD group
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This file is distributed under the terms of the
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GNU General Public License. See the file `License'
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in the root directory of the present distribution,
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or http://www.gnu.org/copyleft/gpl.txt .
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*/
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#include<stdio.h>
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#include<stdlib.h>
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/* qsort - quick sort
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qsort(n,comp,swap)
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unsigned n;
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int (*comp)();
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int (*swap)();
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***** see bsort for parameters
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*/
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static unsigned _rearr(unsigned lb,unsigned ub);
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static void _quick(unsigned lb,unsigned ub);
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static int (*_comp)(unsigned,unsigned), (*_swap)(unsigned,unsigned);
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void Qsort(unsigned n,int (*comp)(),int (*swap)())
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{
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_comp = comp;
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_swap = swap;
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_quick(0,n-1);
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}
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static void _quick(unsigned lb,unsigned ub)
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{
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unsigned j;
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if(lb<ub)
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{
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if((j = _rearr(lb,ub)))
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_quick(lb,j-1);
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_quick(j+1,ub);
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}
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}
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static unsigned _rearr(unsigned lb,unsigned ub)
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{
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do
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{
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while(ub > lb && (*_comp)(ub,lb) >=0) ub--;
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if(ub != lb)
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{
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(*_swap)(ub,lb);
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while(lb<ub && (*_comp)(lb,ub)<=0) lb++;
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if(lb != ub) (*_swap)(lb,ub);
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}
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} while(lb != ub);
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return lb;
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}
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