BellmanFord C++(模板)
/*
******************************************************************************
* Name: BellmanFord
* Description : Find the shortest path from the start point to all other points
* Parameter list: edge - adjacency matrix of the graph
* dist - array of the shortest distance from start point
* path - array of the shortest path
* order - the number of the vertex
* start - start point
* maxNum - max distance means there is no path
*******************************************************************************
*/
void
BellmanFord(
int
*
edge,
int
*
dist,
int
*
path,
const
int
order,
const
int
start,
const
int
maxNum)
{
for
(
int
i
=
0
; i
<
order; i
++
)
{
dist[i]
=
*
(edge
+
start
*
order
+
i);
if
(dist[i]
<
maxNum
&&
i
!=
start)
path[i]
=
start;
else
path[i]
=
-
1
;
}
bool
isChanged
=
true
;
for
(
int
k
=
2
; (k
<
order)
&&
isChanged; k
++
)
{
isChanged
=
false
;
for
(
int
i
=
0
; i
<
order; i
++
)
{
for
(
int
j
=
0
; j
<
order; j
++
)
{
if
(dist[i]
>
dist[j]
+
*
(edge
+
j
*
order
+
i))
{
dist[i]
=
dist[j]
+
*
(edge
+
j
*
order
+
i);
path[i]
=
j;
isChanged
=
true
;
}
}
}
}
}
const
int
maxNum
=
1e8;
int
edge[
7
][
7
]
=
{
{
0
,
6
,
5
,
5
, maxNum, maxNum, maxNum},
{maxNum,
0
, maxNum, maxNum,
-
1
, maxNum, maxNum},
{maxNum,
-
2
,
0
, maxNum,
1
, maxNum, maxNum},
{maxNum, maxNum,
-
2
,
0
, maxNum,
-
1
, maxNum},
{maxNum, maxNum, maxNum, maxNum,
0
, maxNum,
3
},
{maxNum, maxNum, maxNum, maxNum, maxNum,
0
,
3
},
{maxNum, maxNum, maxNum, maxNum, maxNum, maxNum,
0
}
};
int
dist[
7
];
int
path[
7
];
BellmanFord((
int
*
)edge, dist, path,
7
,
0
, maxNum);