poj1703
简单并查集
View Code
#include
<
iostream
>
#include
<
cstdio
>
#include
<
cstdlib
>
#include
<
cstring
>
using
namespace
std;
#define
maxn 100005
int
n, m;
int
f[maxn], father[maxn];
int
getanc(
int
a)
{
if
(a
==
father[a])
return
a;
return
father[a]
=
getanc(father[a]);
}
void
merge(
int
a,
int
b)
{
father[getanc(a)]
=
getanc(b);
}
void
differ(
int
a,
int
b)
{
if
(f[a]
==
-
1
)
f[a]
=
b;
else
merge(f[a], b);
if
(f[b]
==
-
1
)
f[b]
=
a;
else
merge(f[b], a);
}
void
ask(
int
a,
int
b)
{
if
(f[a]
==
-
1
||
f[b]
==
-
1
)
{
printf(
"
Not sure yet.\n
"
);
return
;
}
if
(getanc(a)
==
getanc(b))
{
printf(
"
In the same gang.\n
"
);
return
;
}
if
(getanc(a)
==
getanc(f[b]))
{
printf(
"
In different gangs.\n
"
);
return
;
}
printf(
"
Not sure yet.\n
"
);
}
int
main()
{
//
freopen("t.txt", "r", stdin);
int
t;
scanf(
"
%d
"
,
&
t);
while
(t
--
)
{
memset(f,
-
1
,
sizeof
(f));
scanf(
"
%d%d
"
,
&
n,
&
m);
getchar();
for
(
int
i
=
0
; i
<
n; i
++
)
father[i]
=
i;
for
(
int
i
=
0
; i
<
m; i
++
)
{
char
ch;
int
a, b;
scanf(
"
%c%d%d
"
,
&
ch,
&
a,
&
b);
a
--
;
b
--
;
getchar();
if
(ch
==
'
D
'
)
differ(a, b);
else
ask(a, b);
}
}
return
0
;
}