浅(瞎)谈(吹)最短路径算法总结(Floyd,Bellmen-ford,Dijkstra,Spfa)——————《最短路·终章》
V:点数
E : 边数
Dijkstra
:适用于权值为非负的图的单源最短路径,用斐波那契堆的复杂度
O(E+V log V)
Bellman-Ford
:适用于权值有负值的图的单源最短路径,并且能够检测负圈,复杂度O(VE)
基本标程 AC Pascal代码:
var
n,m,x,y,i,j,bj:longint;
a,b,c,dis:array[-10005..1000005] of longint;
begin
readln(n,m,x,y);
for i:=1 to m do
readln(a[i],b[i],c[i]);
for i:=1 to n do
dis[i]:=maxlongint div 2;
dis[x]:=0;
for i:=1 to n-1 do
begin
bj:=0;
for j:=1 to m do
begin
if dis[b[j]]>dis[a[j]]+c[j] then
begin
dis[b[j]]:=dis[a[j]]+c[j];
bj:=1;
end;
if dis[a[j]]>dis[b[j]]+c[j] then
begin
dis[a[j]]:=dis[b[j]]+c[j];
bj:=1;
end;
end;
if bj=