pku 1679 次最小生成树
代码
#include
<
iostream
>
#include
<
queue
>
#include
<
vector
>
#define
Nmax 105
#define
INF 100000
using
namespace
std;
typedef
struct
{
int
num;
int
st;
}Node;
queue
<
Node
>
q;
Node node;
int
n,m,ANS,col[Nmax][Nmax],tree[Nmax],lowcost[Nmax],dir[Nmax],way[Nmax][Nmax],MAX[Nmax][Nmax],COL[Nmax][Nmax];
bool
v[Nmax];
int
Max(
int
a,
int
b)
{
if
(a
>
b)
return
a;
return
b;
}
void
prim()
{
int
k,j,i;
memset(v,
false
,
sizeof
(v));
for
(i
=
0
;i
<=
n;i
++
)
for
(j
=
0
;j
<=
n;j
++
)way[i][j]
=
false
;
for
(i
=
1
;i
<=
n;i
++
)
{
lowcost[i]
=
col[i][
1
];
dir[i]
=
1
;
}
tree[
0
]
=
1
;
v[
1
]
=
true
;
ANS
=
0
;
for
(k
=
1
;k
<
n;k
++
)
{
int
min
=
INF;
int
min_x;
for
(j
=
1
;j
<=
n;j
++
)
{
if
(
!
v[j]
&&
lowcost[j]
<
min)
{
min
=
lowcost[j];
min_x
=
j;
}
}
v[min_x]
=
true
;
tree[k]
=
min_x;
ANS
+=
min;
int
t
=
dir[min_x];
way[t][min_x]
=
true
;
way[min_x][t]
=
true
;
for
(j
=
1
;j
<=
n;j
++
)
{
if
(
!
v[j]
&&
lowcost[j]
>
col[j][min_x])
{
lowcost[j]
=
col[j][min_x];
dir[j]
=
min_x;
}
}
}
}
void
BFS()
{
for
(
int
i
=
1
;i
<=
n;i
++
)
{
memset(v,
false
,
sizeof
(v));
while
(
!
q.empty())q.pop();
node.num
=
0
;
node.st
=
i;
q.push(node);
v[i]
=
true
;
while
(
!
q.empty())
{
node
=
q.front();
int
t
=
node.st;
int
len
=
node.num;
MAX[i][t]
=
node.num;
q.pop();
v[t]
=
true
;
for
(
int
j
=
1
;j
<=
n;j
++
)
{
if
(COL[t][j]
!=-
1
&&!
v[j])
{
node.st
=
j;
node.num
=
Max(len,COL[t][j]);
v[j]
=
true
;
q.push(node);
}
}
}
}
}
void
PRIN()
{
int
i,j;
for
( i
=
1
;i
<=
n;i
++
)
{
for
( j
=
1
;j
<=
n;j
++
)
{
cout
<<
MAX[i][j]
<<
"
"
;
}
cout
<<
endl;
}
cout
<<
endl;
}
bool
Cal()
{
int
i,j;
for
( i
=
1
;i
<=
n;i
++
)
for
( j
=
1
;j
<=
n;j
++
)
{
if
(way[i][j])MAX[i][j]
=
COL[i][j]
=
col[i][j];
else
MAX[i][j]
=
COL[i][j]
=-
1
;
}
//
PRIN();
BFS();
//
PRIN();
bool
sign_2
=
true
;
for
(i
=
1
;i
<=
n
&&
sign_2;i
++
)
for
(j
=
1
;j
<=
n
&&
sign_2;j
++
)
{
if
(
!
way[i][j]
&&
col[i][j]
==
MAX[i][j]){ sign_2
=
false
;
break
;}
}
return
sign_2;
}
int
main()
{
//
freopen("input.txt","r",stdin);
int
cas;
cin
>>
cas;
while
(cas
--
)
{
scanf(
"
%d%d
"
,
&
n,
&
m);
for
(
int
i
=
0
;i
<=
n;i
++
)
for
(
int
j
=
0
;j
<=
n;j
++
)col[i][j]
=
INF;
while
(m
--
)
{
int
a,b,t;
scanf(
"
%d%d%d
"
,
&
a,
&
b,
&
t);
col[a][b]
=
t;
col[b][a]
=
t;
}
prim();
//
cout<<ANS<<endl;
if
(Cal())cout
<<
ANS
<<
endl;
else
cout
<<
"
Not Unique!
"
<<
endl;
}
return
0
;
}