1. KMP-Prefix Table

2. Algorithm: To compute Prefix Table
Algorithm prefix_table(p) {
m = length(p)
p[1] = 0, k=0
for q = 2 to m do
while((k>0) and (p[k+1) != p[q]))
{ k = p[k] } //only statement
if(p[k+1] = p[q])
k=k+1 //only statement
p[q] = k }
Length between 1 to m

3. Algorithm: To compute Prefix Table
For q = 2 to m do //q=2 and k=0 [m=8]
Whie((k>0) and p[k+1]!=p[q])
False
P[k+1]=p[1]=a and p[q]=e
k = p[k]
Not executed
If (p[k+1]=p[q])
K=k+1
p[q] = k
P[q]=0
P[2]=0
q=3, k=0
q=4, k=1
While
Not Executed
While [k=p[1]=0]
Executed
IF (p[1]=p[3])
True1
If(p[2]=p[4]) [char “e” and “b”) [False]
K=0+1 =1
K=1
P[4] = k
P[4]=0
P[3]=1
q=5, k=0
q=6, k=1
Executed //K=0 If IF
P[5]=1
P[6]=1
Sample example:1 t 1 2 3 4 5 6 7 8 a e b P
m = Length[pattern] = 8 [1-8]
P[1] = 0 // initial condition
K = 0 //pointer to traverse the pattern
q=7, k=1
While
Executed //K=0 If
Executed
K=1
P[7]=1
q=8, k=1
While
Executed//K=0 If
Not executed
K=0
P[8]=0

4. Algorithm: To compute Prefix Table
For q = 2 to m do //q=2 and k=0 [m=8]
Whie((k>0) and p[k+1]!=p[q])
False
P[k+1]=p[1]=a and p[q]=e
k = p[k]
Not executed
If (p[k+1]=p[q])
K=k+1
p[q] = k
P[q]=0
P[2]=0
q=3, k=0
q=4, k=1
While
Not Executed
IF (p[1]=p[3])
True1
If(p[2]=p[4]) [char “b” and “b”) [True]
K=k+1 = 2
K=0+1 =1
K=1
P[4] = k
P[4]=2
P[3]=1
q=5, k=2
q=6, k=3
Executed
Goback step
P[4]!=p[6] If
Executed p[2]!=p[6] //k=0
K=3
P[5]=3
Not executed //p[6]=0
Sample example:2 t 1 2 3 4 5 6 7 8 a b c P
m = Length[pattern] = 8 [1-8]
P[1] = 0 // initial condition
K = 0 //pointer to traverse the pattern
q=7, k=0
While
Not executed If
Executed
K=1
P[7]=1
q=8, k=1
While
Not executed If
Executed
K=2
P[8]=2