D. Reeds wrote:
Robert Fraser Wrote:
D. Reeds wrote:
can anybody help me translate this c code into d, im using D1+tango combo. i'm new to D and got stucked on multi-dimension array part.
int levenshtein_distance(char *s,char*t)
//Compute levenshtein distance between s and t
{
//Step 1
int k,i,j,n,m,cost,*d,distance;
n=strlen(s);
m=strlen(t);
if(n!=0&&m!=0)
{
d=malloc((sizeof(int))*(m+1)*(n+1));
m++;
n++;
//Step 2
for(k=0;k<n;k++)
d[k]=k;
for(k=0;k<m;k++)
d[k*n]=k;
//Step 3 and 4
for(i=1;i<n;i++)
for(j=1;j<m;j++)
{
//Step 5
if(s[i-1]==t[j-1])
cost=0;
else
cost=1;
//Step 6
d[j*n+i]=minimum(d[(j-1)*n+i]+1,d[j*n+i-1]+1,d[(j-1)*n+i-1]+cost);
}
distance=d[n*m-1];
free(d);
return distance;
}
else
return -1; //a negative return value means that one or both strings are empty.
}
int minimum(int a,int b,int c)
//Gets the minimum of three values
{
int min=a;
if(b<min)
min=b;
if(c<min)
min=c;
return min;
}
it is a levenshtein distance algorithm.
Ummm... import tango.stdc.stdlib then copy & paste; that code should
work the same in D as in C. The only changes you should need are:
int k,i,j,n,m,cost,*d,distance;
Which should be changed to:
int k,i,j,n,m,cost,distance;
int* d;
And sizeof(int) -> int.sizeof
i just realized, this code uses c string and c string function therefor its not
utf safe. i do need to convert it to D.
Fun fact: There is already a Levenshtein distance algorithm in Phobos
for D2:
http://www.digitalmars.com/d/2.0/phobos/std_algorithm#levenshteinDistance
I know you said you use D1+Tango, I just thought I should mention it.
The source code is available, if you want to check it out:
http://www.dsource.org/projects/phobos/browser/trunk/phobos/std/algorithm.d
-Lars
