12.6 All Pairs Shortest Paths (Floyd-Warshall)

FOR k=1 TO n  
  FOR i=1 TO n  
    FOR j=1 TO n  
      c(i,j,k) = min(  c(i,j,k-1),  
                       c(i,k,k-1)+c(k,j,k-1)  
                    )

     1        7
 oao ------boo-------coo
7|  ----- |3-----  2
 oo -5-----oeo----1-  oo
 d   8        4   f

k = Ø
a b c d e f
a 1  oo 7 5  oo
b 7  oo 3  oo
c  oo 1 2
d 8  oo
e 4
f
k = {a}
a b c d e f
a 1  oo 7 5  oo
b 7,b-a-c  oo ,b-a-d 3,b-a-e  oo ,b-a-f
c  oo ,c-a-d 1,c-a-e 2,c-a-f
d 8,d-a-e  oo ,d-a-f
e 4,e-a-f
f
k = {a,b}
k = {a,b,c}
k = {a,b,c,d}
k = {a,b,c,d,e}
k = {a,b,c,d,e,f}