poj2492
本来是并查集，我用BFS做的。
View Code
#include
<
iostream
>
#include
<
cstdio
>
#include
<
cstdlib
>
#include
<
cstring
>
using
namespace
std;
#define
maxm 2000005
#define
maxn 2005
struct
Edge
{
int
v, next;
} edge[maxm];
int
m, n;
int
count, head[maxn];
int
q[maxn], front, rear;
int
sex[maxn];
void
addedge(
int
a,
int
b)
{
edge[count].next
=
head[a];
edge[count].v
=
b;
head[a]
=
count;
count
++
;
edge[count].next
=
head[b];
edge[count].v
=
a;
head[b]
=
count;
count
++
;
}
void
input()
{
scanf(
"
%d%d
"
,
&
n,
&
m);
for
(
int
i
=
0
; i
<
m; i
++
)
{
int
a, b;
scanf(
"
%d%d
"
,
&
a,
&
b);
a
--
;
b
--
;
addedge(a, b);
}
}
bool
bfs(
int
s)
{
q[
0
]
=
s;
front
=
0
;
rear
=
1
;
sex[s]
=
0
;
while
(front
!=
rear)
{
int
a
=
q[front
++
];
if
(front
==
maxn)
front
=
0
;
for
(
int
i
=
head[a]; i
!=
-
1
; i
=
edge[i].next)
{
int
v
=
edge[i].v;
if
(sex[v]
==
-
1
)
{
sex[v]
=
1
-
sex[a];
q[rear
++
]
=
v;
if
(rear
==
maxn)
rear
=
0
;
continue
;
}
else
if
(sex[v]
==
sex[a])
return
false
;
}
}
return
true
;
}
int
main()
{
//
freopen("t.txt", "r", stdin);
int
t, s
=
0
;
scanf(
"
%d
"
,
&
t);
while
(t
--
)
{
memset(head,
-
1
,
sizeof
(head));
memset(sex,
-
1
,
sizeof
(sex));
count
=
0
;
s
++
;
printf(
"
Scenario #%d:\n
"
, s);
input();
bool
ans
=
true
;
for
(
int
i
=
0
; i
<
n
&&
ans; i
++
)
if
(sex[i]
==
-
1
)
ans
=
bfs(i);
if
(ans)
printf(
"
No suspicious bugs found!\n\n
"
);
else
printf(
"
Suspicious bugs found!\n\n
"
);
}
return
0
;
}