, . , : Minimum Spanning Tree - MST Shortest Path Tree - SPT. . , 3, MST SPT.
3 , , :
- [A, B, E, D, C] [A, C, D, E, B], 10
- [A, B, E] 5 [A, C, D] 3, 8
- [A, C, D, E] 6 [A, B] 1, - 7
MST - , ( , ).

, MST, 3, , .
SPT , . , SPT, A :
- [A, B] B 1, , [A, C, D, E, B] 10
- [A, B, E] E 5, , [A, C, D, E] 6
- [A, C] C 1, , [A, B, E, D, C] 10
- [A, C, D] D 3, , [A, B, E, D] 8
, , , SPT, 2, 3 . , SPT MST, ( ), MST , .
SPT, MST, - greedy . SPT , , , , , MST, , .
Greedy
Greedy . , Greedy ( ) , ( ). , , Greedy , .
Greedy . , , . , , , , . Greedy , , .
, , .