mirror of
https://github.com/golang/go
synced 2024-11-12 05:30:21 -07:00
8764ebee95
make regexp-dna use bytes not strings (no significant timing change) R=rsc DELTA=149 (138 added, 1 deleted, 10 changed) OCL=32804 CL=32807
83 lines
2.6 KiB
C
83 lines
2.6 KiB
C
/*
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are met:
|
|
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
|
|
* Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
|
|
* Neither the name of "The Computer Language Benchmarks Game" nor the
|
|
name of "The Computer Language Shootout Benchmarks" nor the names of
|
|
its contributors may be used to endorse or promote products derived
|
|
from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
/* -*- mode: c -*-
|
|
*
|
|
* The Great Computer Language Shootout
|
|
* http://shootout.alioth.debian.org/
|
|
*
|
|
* Contributed by Sebastien Loisel
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <math.h>
|
|
|
|
double eval_A(int i, int j) { return 1.0/((i+j)*(i+j+1)/2+i+1); }
|
|
|
|
void eval_A_times_u(int N, const double u[], double Au[])
|
|
{
|
|
int i,j;
|
|
for(i=0;i<N;i++)
|
|
{
|
|
Au[i]=0;
|
|
for(j=0;j<N;j++) Au[i]+=eval_A(i,j)*u[j];
|
|
}
|
|
}
|
|
|
|
void eval_At_times_u(int N, const double u[], double Au[])
|
|
{
|
|
int i,j;
|
|
for(i=0;i<N;i++)
|
|
{
|
|
Au[i]=0;
|
|
for(j=0;j<N;j++) Au[i]+=eval_A(j,i)*u[j];
|
|
}
|
|
}
|
|
|
|
void eval_AtA_times_u(int N, const double u[], double AtAu[])
|
|
{ double v[N]; eval_A_times_u(N,u,v); eval_At_times_u(N,v,AtAu); }
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
int i;
|
|
int N = ((argc == 2) ? atoi(argv[1]) : 2000);
|
|
double u[N],v[N],vBv,vv;
|
|
for(i=0;i<N;i++) u[i]=1;
|
|
for(i=0;i<10;i++)
|
|
{
|
|
eval_AtA_times_u(N,u,v);
|
|
eval_AtA_times_u(N,v,u);
|
|
}
|
|
vBv=vv=0;
|
|
for(i=0;i<N;i++) { vBv+=u[i]*v[i]; vv+=v[i]*v[i]; }
|
|
printf("%0.9f\n",sqrt(vBv/vv));
|
|
return 0;
|
|
}
|