Floyd-Warshall算法描述
1)適用范圍：
a)APSP(All Pairs Shortest Paths)
b)稠密圖效果最佳
c)邊權可正可負
2)算法描述：
a)初始化：dis[u,v]=w[u,v]
b)For k:=1 to n
For i:=1 to n
For j:=1 to n
If dis[i,j]>dis[i,k]+dis[k,j] Then
Dis[I,j]:=dis[I,k]+dis[k,j]
c)算法結束：dis即為所有點對的最短路徑矩陣
3)算法小結：此算法簡單有效，由于三重循環結構緊湊，對于稠密圖，效率要高于執行|V|次Dijkstra算法。時間復雜度O(n^3)。
考慮下列變形：如(I,j)∈E則dis[I,j]初始為1,else初始為0，這樣的Floyd算法最后的最短路徑矩陣即成為一個判斷I,j是否有通路的矩陣。更簡單的，我們可以把dis設成boolean類型，則每次可以用“dis[I,j]:=dis[I,j]or(dis[I,k]and dis[k,j])”來代替算法描述中的藍色部分，可以更直觀地得到I,j的連通情況。
This program is copyrighted by it s author and you are granted a free license
to use the program for non-commercial purposes. If you are interested in
using the program for commercial purposes please contact Kevin W. Russell
at CIS 71551,253 for licensing information.
unix環境高級編程英文版，很經典的一本書
Advanced Programming in the UNIX® Environment: Second Edition
By W. Richard Stevens, Stephen A. Rago
Publisher: Addison Wesley Professional
Pub Date: June 17, 2005
ISBN: 0201433079
Pages: 960
Compile SQLite using the cross-compiler such as arm-linux-gcc
first, get sqlite-3.3.6.tar.gz from www.sqlite.org
unzip it,
#tar -zxvf sqlite-3.3.6.tar.gz
change into the sqlite-3.3.6 directory
cd sqlite-3.3.6
