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Optimal binary search tree dynamic programming | PDF
Optimal Binary Search Tree
Dr. P. Subathra
Prof/ IT
KAMARAJ College of Engg. & Tech
(AUTONOMOUS)
Madurai
Tamil Nadu
India
• If probabilities of searching for elements of a set are
known—e.g., from accumulated data about past
searches—it is natural to pose a question about an
optimal binary search tree for which the average
number of comparisons in a search is the smallest
possible.
• we limit our discussion to minimizing the average
number of comparisons in a successful search.
• The method can be extended to include unsuccessful
searches as well.
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
2
• The total number of binary search trees with n
keys is equal to the nth Catalan number
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
3
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
4
OBST CREATION
(j-i)=0
Item 1 2 3 4
Key 10 20 30 40
Freq 4 2 6 3
i j 0 1 2 3 4
0
1
2
3
4
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
5
OBST CREATION
No. of Nodes = 0
(j-i)=0
(0-0) = 0 = C[0,0]
(1-1) = 0 = C[1,1]
(2-2) = 0 = C[2,2]
(3-3) = 0 = C[3,3]
(4-4) = 0 = C[4,4]
Item 1 2 3 4
Key 10 20 30 40
Freq 4 2 6 3
i j 0 1 2 3 4
0 0
1 0
2 0
3 0
4 0
6
OBST CREATION
No. of Nodes = 1
(j-i)=1
(1-0) = 1 = C[0,1]
(2-1) = 1 = C[1,2]
(3-2) = 1 = C[2,3]
(4-3) = 1 = C[3,4]
Item 1 2 3 4
Key 10 20 30 40
Freq 4 2 6 3
i j 0 1 2 3 4
0 0
1 0
2 0
3 0
4 0
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
7
OBST CREATION
No. of Nodes = 1
(j-i)=1
(1-0) = 1 = C[0,1] = 41
(2-1) = 1 = C[1,2]
(3-2) = 1 = C[2,3]
(4-3) = 1 = C[3,4]
Item 1 2 3 4
Key 10 20 30 40
Freq 4 2 6 3
i j 0 1 2 3 4
0 0 41
1 0
2 0
3 0
4 0
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
8
OBST CREATION
No. of Nodes = 1
(j-i)=1
(1-0) = 1 = C[0,1] = 41
(2-1) = 1 = C[1,2] = 22
(3-2) = 1 = C[2,3]
(4-3) = 1 = C[3,4]
Item 1 2 3 4
Key 10 20 30 40
Freq 4 2 6 3
i j 0 1 2 3 4
0 0 41
1 0 22
2 0
3 0
4 0
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
9
OBST CREATION
No. of Nodes = 1
(j-i)=1
(1-0) = 1 = C[0,1] = 41
(2-1) = 1 = C[1,2] = 22
(3-2) = 1 = C[2,3] = 63
(4-3) = 1 = C[3,4]
Item 1 2 3 4
Key 10 20 30 40
Freq 4 2 6 3
i j 0 1 2 3 4
0 0 41
1 0 22
2 0 63
3 0
4 0
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
10
OBST CREATION
No. of Nodes = 1
(j-i)=1
(1-0) = 1 = C[0,1] = 41
(2-1) = 1 = C[1,2] = 22
(3-2) = 1 = C[2,3] = 63
(4-3) = 1 = C[3,4] = 34
Item 1 2 3 4
Key 10 20 30 40
Freq 4 2 6 3
i j 0 1 2 3 4
0 0 41
1 0 22
2 0 63
3 0 34
4 0
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
11
OBST CREATION
No. of Nodes = 2
(j-i)=2
(2-0) = 2 = C[0,2]
(3-1) = 2 = C[1,3]
(4-2) = 2 = C[2,4]
Item 1 2 3 4
Key 10 20 30 40
Freq 4 2 6 3
i j 0 1 2 3 4
0 0 41
1 0 22
2 0 63
3 0 34
4 0
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
12
OBST CREATION
No. of Nodes = 2 : (1&2)
C[0,2] : i = 0; j =2; k = 1, 2;
k =1
C[0, 1-1] + C[1, 2]
= min k=2 + (W1+W2)
C[0, 2-1] + C[2, 2]
= min k= 1 (0+2)
k= 2 (0+6)
= 2 + 6 = 81
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81
1 0 22
2 0 63
3 0 34
4 0
+ (4+2)
13
OBST CREATION
No. of Nodes = 2 : (2&3)
C[1,3] : i = 1; j =3; k = 2, 3;
k =2
C[1, 2-1] + C[2, 3]
= min k=3 + (W2+W3)
C[1, 3-1] + C[3, 3]
= min k= 2 (0+6)
k= 3 (2+0)
= 2 + 8 = 103
Item 1 2 3 4
Key 10 20 30 40
Freq
(W)
4 2 6 3
i j 0 1 2 3 4
0 0 41 81
1 0 22 103
2 0 63
3 0 34
4 0
+ (2+6)
14
OBST CREATION
No. of Nodes = 2 : (3&4)
C[2,4] : i = 2; j =4; k = 3, 4;
k =3
C[2, 3-1] + C[3, 4]
= min k=4 + (W2+W3)
C[2, 4-1] + C[4, 4]
= min k= 3 (0+3)
k= 4 (6+0)
= 3 + 9 = 123
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81
1 0 22 103
2 0 63 123
3 0 34
4 0
+ (6+3)
15
OBST CREATION
No. of Nodes = 3 :
(j-i) = 3
(3-0) = 3 = C[0,3]
(4-1) = 3 = C[1,4]
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81
1 0 22 103
2 0 63 123
3 0 34
4 0
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
16
OBST CREATION
No. of Nodes = 3 : (1,2&3)
C[0,3] : i = 0; j =3; k = 1,2,3;
k =1
C[0, 1-1] + C[1, 3]
= min k=2
C[0, 2-1] + C[2, 3]
k=3 + (W1+W2+W3)
C[0, 3-1] + C[3, 3]
= min k= 1 (0+10)
k= 2 (4+6)
k= 3 (8+0)
= 8 + 12 = 203
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203
1 0 22 103
2 0 63 123
3 0 34
4 0
+ (4+2+6)
17
OBST CREATION
No. of Nodes = 3 : (2,3 & 4)
C[1,4] : i = 1; j =4; k = 2,3,4;
k =2
C[1, 2-1] + C[2, 4]
= min k=3
C[1, 3-1] + C[3, 4]
k=4 + (W2+W3+W4)
C[1, 4-1] + C[4, 4]
= min k= 2 (0+12)
k= 3 (2+3)
k= 4 (10+0)
= 5 + 11 = 163
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203
1 0 22 103 163
2 0 63 123
3 0 34
4 0
+ (2+6+3)
18
OBST CREATION
No. of Nodes = 4 :
(j-i) = 4
(4-0) = 4 = C[0,4]
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203
1 0 22 103 163
2 0 63 123
3 0 34
4 0
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
19
OBST CREATION
No. of Nodes = 4 : (1,2,3 & 4)
C[0,4] : i = 0; j =4; k = 1,2,3,4;
k=1
C[0, 1-1] + C[1, 4]
k =2
C[0, 2-1] + C[2, 4]
= min k=3
C[0, 3-1] + C[3, 4]
k=4 + (W1+W2+W3+W4)
C[0, 4-1] + C[4, 4]
= min k=1 (0+16)
k= 2 (4+12)
k= 3 (8+3)
k= 4 (20+0)
= 11 + 15 = 263
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
+ (4+2+6+3)
20
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
r(0, 4)
3
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
21
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
r(0, 4)
3
r(left, root-1) r(root, right)
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
22
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
r(0, 4)
r(0,2) r(3,4)
3
r(left, root-1) r(root, right)
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
23
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
r(0, 4)
r(0,2) r(3,4)
3
1 4
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
24
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
r(0, 4)
r(0,2) r(3,4)
3
1 4
r(left, root-1) r(root, right)
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
25
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
r(0, 4)
r(0,2) r(3,4)
3
1 4
r(0,0) r(1,2)
r(left, root-1) r(root, right)
2
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
26
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
r(0, 4)
r(0,2) r(3,4)
3
1 4
r(0,0) r(1,2)
r(left, root-1) r(root, right)
2
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
27
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
r(0, 4)
r(0,2) r(3,4)
3
1 4
r(0,0) r(1,2)
r(left, root-1) r(root, right)
2
r(1,1) r(2,2) Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
28
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
r(0, 4)
r(0,2) r(3,4)
3
1 4
r(0,0) r(1,2)
r(left, root-1) r(root, right)
2
r(1,1) r(2,2) Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
29
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
r(0, 4)
r(0,2) r(3,4)
3
1 4
r(0,0) r(1,2)
r(left, root-1) r(root, right)
2
r(1,1) r(2,2) Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
30
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
r(0, 4)
r(0,2) r(3,4)
3
1 4
r(0,0) r(1,2)
r(left, root-1) r(root, right)
2
r(1,1) r(2,2)
r(3,3) r(4,4)
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
31
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
r(0, 4)
r(0,2) r(3,4)
3
1 4
r(0,0) r(1,2)
r(left, root-1) r(root, right)
2
r(1,1) r(2,2)
r(3,3) r(4,4)
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
32
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
3
1 4
2
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
33
OBST CREATION
Item 1 2 3 4
Key 10 20 30 40
Freq (W) 4 2 6 3
i j 0 1 2 3 4
0 0 41 81 203 263
1 0 22 103 163
2 0 63 123
3 0 34
4 0
3
1 4
2
Dr. P. Subathra, KAMARAJ College of Engg &
Tech (AUTONOMOUS), Madurai,
Tamil Nadu, India
34
END…!!!

Optimal binary search tree dynamic programming

  • 1.
    Optimal Binary SearchTree Dr. P. Subathra Prof/ IT KAMARAJ College of Engg. & Tech (AUTONOMOUS) Madurai Tamil Nadu India
  • 2.
    • If probabilitiesof searching for elements of a set are known—e.g., from accumulated data about past searches—it is natural to pose a question about an optimal binary search tree for which the average number of comparisons in a search is the smallest possible. • we limit our discussion to minimizing the average number of comparisons in a successful search. • The method can be extended to include unsuccessful searches as well. Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 2
  • 3.
    • The totalnumber of binary search trees with n keys is equal to the nth Catalan number Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 3
  • 4.
    Dr. P. Subathra,KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 4
  • 5.
    OBST CREATION (j-i)=0 Item 12 3 4 Key 10 20 30 40 Freq 4 2 6 3 i j 0 1 2 3 4 0 1 2 3 4 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 5
  • 6.
    OBST CREATION No. ofNodes = 0 (j-i)=0 (0-0) = 0 = C[0,0] (1-1) = 0 = C[1,1] (2-2) = 0 = C[2,2] (3-3) = 0 = C[3,3] (4-4) = 0 = C[4,4] Item 1 2 3 4 Key 10 20 30 40 Freq 4 2 6 3 i j 0 1 2 3 4 0 0 1 0 2 0 3 0 4 0 6
  • 7.
    OBST CREATION No. ofNodes = 1 (j-i)=1 (1-0) = 1 = C[0,1] (2-1) = 1 = C[1,2] (3-2) = 1 = C[2,3] (4-3) = 1 = C[3,4] Item 1 2 3 4 Key 10 20 30 40 Freq 4 2 6 3 i j 0 1 2 3 4 0 0 1 0 2 0 3 0 4 0 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 7
  • 8.
    OBST CREATION No. ofNodes = 1 (j-i)=1 (1-0) = 1 = C[0,1] = 41 (2-1) = 1 = C[1,2] (3-2) = 1 = C[2,3] (4-3) = 1 = C[3,4] Item 1 2 3 4 Key 10 20 30 40 Freq 4 2 6 3 i j 0 1 2 3 4 0 0 41 1 0 2 0 3 0 4 0 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 8
  • 9.
    OBST CREATION No. ofNodes = 1 (j-i)=1 (1-0) = 1 = C[0,1] = 41 (2-1) = 1 = C[1,2] = 22 (3-2) = 1 = C[2,3] (4-3) = 1 = C[3,4] Item 1 2 3 4 Key 10 20 30 40 Freq 4 2 6 3 i j 0 1 2 3 4 0 0 41 1 0 22 2 0 3 0 4 0 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 9
  • 10.
    OBST CREATION No. ofNodes = 1 (j-i)=1 (1-0) = 1 = C[0,1] = 41 (2-1) = 1 = C[1,2] = 22 (3-2) = 1 = C[2,3] = 63 (4-3) = 1 = C[3,4] Item 1 2 3 4 Key 10 20 30 40 Freq 4 2 6 3 i j 0 1 2 3 4 0 0 41 1 0 22 2 0 63 3 0 4 0 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 10
  • 11.
    OBST CREATION No. ofNodes = 1 (j-i)=1 (1-0) = 1 = C[0,1] = 41 (2-1) = 1 = C[1,2] = 22 (3-2) = 1 = C[2,3] = 63 (4-3) = 1 = C[3,4] = 34 Item 1 2 3 4 Key 10 20 30 40 Freq 4 2 6 3 i j 0 1 2 3 4 0 0 41 1 0 22 2 0 63 3 0 34 4 0 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 11
  • 12.
    OBST CREATION No. ofNodes = 2 (j-i)=2 (2-0) = 2 = C[0,2] (3-1) = 2 = C[1,3] (4-2) = 2 = C[2,4] Item 1 2 3 4 Key 10 20 30 40 Freq 4 2 6 3 i j 0 1 2 3 4 0 0 41 1 0 22 2 0 63 3 0 34 4 0 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 12
  • 13.
    OBST CREATION No. ofNodes = 2 : (1&2) C[0,2] : i = 0; j =2; k = 1, 2; k =1 C[0, 1-1] + C[1, 2] = min k=2 + (W1+W2) C[0, 2-1] + C[2, 2] = min k= 1 (0+2) k= 2 (0+6) = 2 + 6 = 81 Item 1 2 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 1 0 22 2 0 63 3 0 34 4 0 + (4+2) 13
  • 14.
    OBST CREATION No. ofNodes = 2 : (2&3) C[1,3] : i = 1; j =3; k = 2, 3; k =2 C[1, 2-1] + C[2, 3] = min k=3 + (W2+W3) C[1, 3-1] + C[3, 3] = min k= 2 (0+6) k= 3 (2+0) = 2 + 8 = 103 Item 1 2 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 1 0 22 103 2 0 63 3 0 34 4 0 + (2+6) 14
  • 15.
    OBST CREATION No. ofNodes = 2 : (3&4) C[2,4] : i = 2; j =4; k = 3, 4; k =3 C[2, 3-1] + C[3, 4] = min k=4 + (W2+W3) C[2, 4-1] + C[4, 4] = min k= 3 (0+3) k= 4 (6+0) = 3 + 9 = 123 Item 1 2 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 1 0 22 103 2 0 63 123 3 0 34 4 0 + (6+3) 15
  • 16.
    OBST CREATION No. ofNodes = 3 : (j-i) = 3 (3-0) = 3 = C[0,3] (4-1) = 3 = C[1,4] Item 1 2 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 1 0 22 103 2 0 63 123 3 0 34 4 0 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 16
  • 17.
    OBST CREATION No. ofNodes = 3 : (1,2&3) C[0,3] : i = 0; j =3; k = 1,2,3; k =1 C[0, 1-1] + C[1, 3] = min k=2 C[0, 2-1] + C[2, 3] k=3 + (W1+W2+W3) C[0, 3-1] + C[3, 3] = min k= 1 (0+10) k= 2 (4+6) k= 3 (8+0) = 8 + 12 = 203 Item 1 2 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 1 0 22 103 2 0 63 123 3 0 34 4 0 + (4+2+6) 17
  • 18.
    OBST CREATION No. ofNodes = 3 : (2,3 & 4) C[1,4] : i = 1; j =4; k = 2,3,4; k =2 C[1, 2-1] + C[2, 4] = min k=3 C[1, 3-1] + C[3, 4] k=4 + (W2+W3+W4) C[1, 4-1] + C[4, 4] = min k= 2 (0+12) k= 3 (2+3) k= 4 (10+0) = 5 + 11 = 163 Item 1 2 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 1 0 22 103 163 2 0 63 123 3 0 34 4 0 + (2+6+3) 18
  • 19.
    OBST CREATION No. ofNodes = 4 : (j-i) = 4 (4-0) = 4 = C[0,4] Item 1 2 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 1 0 22 103 163 2 0 63 123 3 0 34 4 0 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 19
  • 20.
    OBST CREATION No. ofNodes = 4 : (1,2,3 & 4) C[0,4] : i = 0; j =4; k = 1,2,3,4; k=1 C[0, 1-1] + C[1, 4] k =2 C[0, 2-1] + C[2, 4] = min k=3 C[0, 3-1] + C[3, 4] k=4 + (W1+W2+W3+W4) C[0, 4-1] + C[4, 4] = min k=1 (0+16) k= 2 (4+12) k= 3 (8+3) k= 4 (20+0) = 11 + 15 = 263 Item 1 2 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 + (4+2+6+3) 20
  • 21.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 r(0, 4) 3 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 21
  • 22.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 r(0, 4) 3 r(left, root-1) r(root, right) Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 22
  • 23.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 r(0, 4) r(0,2) r(3,4) 3 r(left, root-1) r(root, right) Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 23
  • 24.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 r(0, 4) r(0,2) r(3,4) 3 1 4 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 24
  • 25.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 r(0, 4) r(0,2) r(3,4) 3 1 4 r(left, root-1) r(root, right) Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 25
  • 26.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 r(0, 4) r(0,2) r(3,4) 3 1 4 r(0,0) r(1,2) r(left, root-1) r(root, right) 2 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 26
  • 27.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 r(0, 4) r(0,2) r(3,4) 3 1 4 r(0,0) r(1,2) r(left, root-1) r(root, right) 2 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 27
  • 28.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 r(0, 4) r(0,2) r(3,4) 3 1 4 r(0,0) r(1,2) r(left, root-1) r(root, right) 2 r(1,1) r(2,2) Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 28
  • 29.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 r(0, 4) r(0,2) r(3,4) 3 1 4 r(0,0) r(1,2) r(left, root-1) r(root, right) 2 r(1,1) r(2,2) Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 29
  • 30.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 r(0, 4) r(0,2) r(3,4) 3 1 4 r(0,0) r(1,2) r(left, root-1) r(root, right) 2 r(1,1) r(2,2) Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 30
  • 31.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 r(0, 4) r(0,2) r(3,4) 3 1 4 r(0,0) r(1,2) r(left, root-1) r(root, right) 2 r(1,1) r(2,2) r(3,3) r(4,4) Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 31
  • 32.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 r(0, 4) r(0,2) r(3,4) 3 1 4 r(0,0) r(1,2) r(left, root-1) r(root, right) 2 r(1,1) r(2,2) r(3,3) r(4,4) Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 32
  • 33.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 3 1 4 2 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 33
  • 34.
    OBST CREATION Item 12 3 4 Key 10 20 30 40 Freq (W) 4 2 6 3 i j 0 1 2 3 4 0 0 41 81 203 263 1 0 22 103 163 2 0 63 123 3 0 34 4 0 3 1 4 2 Dr. P. Subathra, KAMARAJ College of Engg & Tech (AUTONOMOUS), Madurai, Tamil Nadu, India 34
  • 35.