Levenshtein distance (substitution and insertion)

levenshtein.cpp

int cambios(string s1, string s2) {
    int l1 = s1.size();
    int l2 = s2.size();
    
    int *A = new int[l2];
    
    int i, j;
    
    for(i=0; i<=l2; i++) {
        A[i] = i;
    }
    for(i=0; i<l1; i++) {
        A[0] = i+1;
        int x = i;
        
        for(j=0; j<l2; j++) {
            int y = A[j+1];
            
            if(s1[i] == s2[j])
                A[j+1] = x;
            else {
                int n;
                if(y < x) 
                    n = y;
                else
                    n = x;

                if(A[j] < n)
                    A[j+1] = A[j];
                else
                    A[j+1] = n + 1;
            }
            x = y;
        }
    }
    
    return A[l2];
}