words transform approach

gistfile1.cpp

int string_compare(char *s, char *t, int i, int j, )
// s is inut text
// t is target
{
    int k; /* counter */
    int opt[3]; /* cost of the three options */
    int lowest_cost; /* lowest cost */
 
    if (i == 0) return(j * cost.insertion);
    if (j == 0) return(i * cost.deletion);
    if (i==1 && j==1 && s[i] == t[j]) {
       return 0;     
    }
    
    if (s[i] == t[j]) {
       return string_compare(s,t,i-1,j-1);
    } else {
       cost1 = cost2 = cost3 = INT.MAX
       // replace a character
       if ( s[:i-1].append(t[j])  in dictionary) { 
          cost1 = string_compare(s,t,i-1,j-1) + cost.replace 
       }  
                 
       // extra character in input. delete one  
       if (s[:i-1] in dictionary) { 
          cost2 = string_compare(s,t,i-1,j) + cost.deletion 
       }

       // extra character in target. insert one
       if (s[:i].append(t[j]) in dictionary) {  
           cost3 = string_compare(s,t,i,j-1) + cost.insertion 
       } 

       lowest_cost = min ( cost1, cost2, cost3)
        
    }
    
 
    return( lowest_cost );
}