mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-18 12:29:21 +00:00
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1057 91177308-0d34-0410-b5e6-96231b3b80d8
76 lines
1.1 KiB
C
76 lines
1.1 KiB
C
/* -*- mode: c -*-
|
|
* $Id$
|
|
* http://www.bagley.org/~doug/shootout/
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <math.h>
|
|
#include <stdio.h>
|
|
|
|
#define IM 139968
|
|
#define IA 3877
|
|
#define IC 29573
|
|
|
|
double
|
|
gen_random(double max) {
|
|
static long last = 42;
|
|
return( max * (last = (last * IA + IC) % IM) / IM );
|
|
}
|
|
|
|
void
|
|
heapsort(int n, double *ra) {
|
|
int i, j;
|
|
int ir = n;
|
|
int l = (n >> 1) + 1;
|
|
double rra;
|
|
|
|
for (;;) {
|
|
if (l > 1) {
|
|
rra = ra[--l];
|
|
} else {
|
|
rra = ra[ir];
|
|
ra[ir] = ra[1];
|
|
if (--ir == 1) {
|
|
ra[1] = rra;
|
|
return;
|
|
}
|
|
}
|
|
|
|
i = l;
|
|
j = l << 1;
|
|
while (j <= ir) {
|
|
if (j < ir && ra[j] < ra[j+1]) {
|
|
++j;
|
|
}
|
|
if (rra < ra[j]) {
|
|
ra[i] = ra[j];
|
|
j += (i = j);
|
|
} else {
|
|
j = ir + 1;
|
|
}
|
|
}
|
|
ra[i] = rra;
|
|
}
|
|
}
|
|
|
|
int
|
|
main(int argc, char *argv[]) {
|
|
int N = ((argc == 2) ? atoi(argv[1]) : 10);
|
|
double *ary;
|
|
int i;
|
|
|
|
/* create an array of N random doubles */
|
|
ary = (double *)malloc((N+1) * sizeof(double));
|
|
for (i=1; i<=N; i++) {
|
|
ary[i] = gen_random(1);
|
|
}
|
|
|
|
heapsort(N, ary);
|
|
|
|
printf("%f\n", ary[N]);
|
|
|
|
free(ary);
|
|
return(0);
|
|
}
|
|
|