Cracking The Coding Interview: Chapter 1 Solutions in PeopleCode

(Some functions can be improved using smarter features, comments welcome)

# 1

Function isUnique(&checkLetters As string) Returns boolean
 
   Local number &I = 0;
   Local array of string &holder;
 
   &holder = Split(&checkLetters, "");
   &holder.Sort("A");
   If &holder.Len > 128 Then
            Return false;
   End-If;
   While &holder.Next(&I)
      If &holder.Len > &I Then
         If &holder [&I] = &holder [&I + 1] Then
            Return False;
         End-If;
      End-If;
   End-While;
   Return True;
 
End-Function;

# 2

Function checkPermute(&A As string, &B As string) Returns boolean
 
   Local array of string &hold1, &hold2;
   Local string &C, &D;
   If Not Len(&A) = Len(&B) Then
      Return False;
   End-If;
   &hold1 = Split(&A, "");
   &hold2 = Split(&B, "");
   &hold1.Sort("A");
   &hold2.Sort("A");
   &C = &hold1.Join("");
   &D = &hold2.Join("");
   Return Exact(&C, &D);
 
End-Function;

# 3

Function urlify(&url As string) Returns string
 
   Local string &url20;
 
   &url20 = LTrim(RTrim(&url));
   &url20 = Substitute(&url20, " ", "%20");
   Return &url20;
 
End-Function;

# 4

Function palinPerm(&pp As string) Returns boolean
 
   Local array of string &hold;
   Local string &temp;
   Local number &I, &K, &E, &cnt;
   Local array of number &counterArr;
 
 
   &K = 0;
   &temp = Substitute(&pp, " ", "");
   &hold = Split(&temp, "");
   &hold.Sort("A");
   &counterArr = CreateArrayRept(1, &hold.Len);
   &cnt = 1;
 
   For &I = 1 To &hold.Len
      &K = &I;
      While &hold.Next(&K)
         If &hold [&I] = &hold [&K] Then
            &counterArr [&cnt] = &counterArr [&cnt] + 1;
         Else
            &I = &K - 1;
            &cnt = &cnt + 1;
            Break;
         End-If;
      End-While;
   End-For;
 
   For &E = 1 To &cnt
   
      If &counterArr [&E] > 1 Then
         If Mod(&counterArr [&E], 2) = 1 Then
            Return False;
         End-If;
      Else
         If &counterArr [&E] <> 1 Then
            Return False;
         End-If;
      End-If;
   
   End-For;
 
   Return True;
 
End-Function;

# 5

Function OneAway(&str1 As string, &str2 As string) Returns boolean
 
   Local array of string &hold1, &hold2;
   Local number &I, &width, &exception;
   &hold1 = Split(&str1, "");
   &hold2 = Split(&str2, "");
   &hold1.Sort("A");
   &hold2.Sort("A");
 
   If Abs(&hold1.Len - &hold2.Len) > 1 Then
      Return False;
   End-If;
   If &hold1.Len > &hold2.Len Then
      &width = &hold2.Len
   Else
      &width = &hold1.Len
   End-If;
   &exception = 0;
   For &I = 1 To &width Step 1
      If &hold1 [&I] <> &hold2 [&I] Then
         &exception = &exception + 1;
      End-If;
   End-For;
   If &exception > 1 Then
      Return False;
   End-If;
 
   Return True;
End-Function;

# 6

Function compString(&str As string) Returns string
 
   Local array of string &hold, &sorted, &temp;
   Local number &I, &S, &cnt;
   Local string &item, &result;
   &hold = Split(&str, "");
   &sorted = &hold.Sort("A");
   &cnt = 0;
   &I = 0;
   While &hold.Next(&I)
      &item = &hold [&I];
      &temp.Push(&item);
      &S = 0;
      While &sorted.Next(&S);
           If &hold [&I] = &item Then
                &cnt = &cnt + 1;
           End-If;
      End-While;
      &temp.Push(&cnt);
      &cnt=0;
   End-While;

   &result = &temp.Join();
 
   If &hold.Len <= &temp.Len Then
      Return &str;
   Else
      Return &result;
   End-If;
 
End-Function;

# 7

Function rotateMatrixClockWise90(&origM As array of array of number, &dim As number) Returns array of array of number

   Local array of array of number &rotatedM;
   Local number &y, &x, &first, &last, &i, &offset, &top;
 
   &rotatedM = &origM.Clone();
   &y = &dim;
   For &x = 1 To &dim / 2 Step 1
   
      &first = &x;
      &last = &y;
   
      For &i = &first To &last Step 1
       
         &offset = &i - &first;
         &top = &rotatedM [&first][&i];
       
         &rotatedM [&first][&i] = &rotatedM [&last - &offset][&first];
         &rotatedM [&last - &offset][&first] = &rotatedM [&last][&last - &offset];
         &rotatedM [&last][&last - &offset] = &rotatedM [&i][&last];
         &rotatedM [&i][&last] = &top;
      End-For;
      &y = &y - 1;
   End-For;
   Return &rotatedM;
End-Function;

# 8

Function zeroMatrix(&origM As array of array of number, &row As number, &col As number) Returns array of array of number
   Local array of array of number &zeroMat;
   Local number &i, &j, &r, &c;
   &zeroMat = &origM.Clone();
   For &i = 1 To &row
      For &j = 1 To &col
         If &zeroMat [&i][&j] = 0 Then
            For &c = 1 To &col
               &origMat [&i][&c] = 0;
            End-For;
            For &r = 1 To &row
               &origMat [&r][&j] = 0;
            End-For;
         End-If;
      End-For;
   End-For;
   Return &origMat;
End-Function;

# 9

Function isRotation(&orig As string, &test As string) Returns boolean
 
   Local string &dup;
 
   &dup = &orig | &orig;
 
   return isSubstring(&orig, &test);
 
 
   Return False;
End-Function;