strep2.c

王小平《遗传算法——理论、应用与软件实现》随书光盘

/*   Function news1=strep2(s1)

     Replaces '*','^' and '/' with '.*', '.^' and './'
     
     
     CMEX file version of strrep6.m
     
     
     
     Author:	Mark Hinchliffe
     
     Date:	26 October 1995
*/     
     
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "mex.h"

/* Gateway routine */

void mexFunction(
	int nlhs, Matrix *plhs[],
	int nrhs, Matrix *prhs[])
{
	char *s1;
	char *news1;
	int n,i,ctr;
	int len;

/* allocate memory and read input string , s1 */

	n = mxGetN(prhs[0])+1;
	s1 = mxCalloc(n,sizeof(char));
	mxGetString(prhs[0],s1,n);	
	
	
/* count number of occurences of *, / and ^ in string s1 */

	ctr=0;
	
	for(i=0; i<n; i++)
	{
		if((s1[i] == '*') || (s1[i] == '/') 
					|| (s1[i] == '^'))
		{			
			ctr+=1;}
			
		
	}
	
/* allocate memory for new version of string, news1 */		
	
	news1 = mxCalloc((n+ctr),sizeof(char));
	
		
/* Call string replacement routine */

	strrep(news1, s1);
	
	
/* Create output string and free memory */

	plhs[0] = mxCreateString(news1);
	
	mxFree(s1);
	mxFree(news1);
}

strrep(char news1[],char s1[])
{
	int i,j;
	int len=strlen(s1);
	
	
/* create new string */
	
	j=0;

	
	for(i=0; i<len; i++)
	{
		if((s1[i] == '*') || (s1[i] == '/') 
					|| (s1[i] == '^'))
		{			
			news1[j] = '.';
			j += 1;}
			
		
		news1[j]=s1[i];
		j += 1;
		
	}
		
	return ;	

}