forked from lijiext/lammps
44 lines
1.1 KiB
C
44 lines
1.1 KiB
C
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/* Numerical Recipes heap sort, modified to be like C library qsort */
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/* accepts arbitrary objects to be sorted, user provides compare function
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this routine sorts a F77-style array indexed from 1-n
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thus you MUST call it from C with hpsort(ra-1, ) to offset C ptr by -1
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also added multiply-array-index-by-size to enable arbitrary objects
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*/
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void hpsort(char *ra, int n, int size,
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int (*cmp)(const void *, const void *))
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{
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unsigned long i,ir,j,l;
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char *rra;
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if (n < 2) return;
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l = (n >> 1)+1;
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ir = n;
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rra = (char *) malloc(size);
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for (;;) {
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if (l > 1) {
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memcpy(rra,&ra[(--l)*size],size);
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} else {
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memcpy(rra,&ra[ir*size],size);
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memcpy(&ra[ir*size],&ra[1*size],size);
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if (--ir == 1) {
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memcpy(&ra[1*size],rra,size);
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break;
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}
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}
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i = l;
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j = l+l;
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while (j <= ir) {
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if (j < ir && (*cmp)(&ra[j*size],&ra[(j+1)*size]) < 0) j++;
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if ((*cmp)(rra,&ra[j*size]) < 0) {
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memcpy(&ra[i*size],&ra[j*size],size);
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i = j;
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j <<= 1;
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} else j = ir+1;
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}
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memcpy(&ra[i*size],rra,size);
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}
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free(rra);
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}
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