## digitalmars.D.learn - need help convert c code

• D. Reeds (48/48) Jul 16 2009 can anybody help me translate this c code into d, im using D1+tango comb...
• Robert Fraser (8/59) Jul 16 2009 Ummm... import tango.stdc.stdlib then copy & paste; that code should
• D. Reeds (2/66) Jul 16 2009 thank you very much.
• D. Reeds (2/66) Jul 16 2009 i just realized, this code uses c string and c string function therefor ...
• Lars T. Kyllingstad (8/75) Jul 17 2009 Fun fact: There is already a Levenshtein distance algorithm in Phobos
• D. Reeds (2/11) Jul 17 2009 awesome, exactly what im looking for. thanks alot.
• bearophile (6/9) Jul 17 2009 For more than a year there's a Levenshtein distance for D1 in my dlibs t...
```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.
```
Jul 16 2009
Robert Fraser <fraserofthenight gmail.com> writes:
```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
```
Jul 16 2009
```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

thank you very much.
```
Jul 16 2009
```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.
```
Jul 16 2009
"Lars T. Kyllingstad" <public kyllingen.NOSPAMnet> writes:
```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
```
Jul 17 2009
```Lars T. Kyllingstad Wrote:
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

awesome, exactly what im looking for. thanks alot.
```
Jul 17 2009
"Lars T. Kyllingstad" <public kyllingen.NOSPAMnet> writes:
```D. Reeds wrote:
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

awesome, exactly what im looking for. thanks alot.

No problem. :)

Here's a small warning, though: You should be aware that D2 is the
experimental branch of the D language. It is very different from D1, so
it is unlikely that you can just copy and paste the code into your program.

-Lars
```
Jul 17 2009
bearophile <bearophileHUGS lycos.com> writes:
```Lars T. Kyllingstad:
Fun fact: There is already a Levenshtein distance algorithm in Phobos
for D2:
http://www.digitalmars.com/d/2.0/phobos/std_algorithm#levenshteinDistance

For more than a year there's a Levenshtein distance for D1 in my dlibs too, and
it's quite faster than the one in Phobos2 (but take a look at the software
licence):
http://www.fantascienza.net/leonardo/so/libs_d.zip
See functions "editDistance" and "editDistanceFast" in the "func.d" module.

Bye,
bearophile
```
Jul 17 2009