#include
<
iostream
>
#include
<
vector
>
using
namespace
std;
#define
N 40010
typedef pair
<
int
,
int
>
PAIR;
int
m, n;
vector
<
PAIR
>
query[N], map[N];
int
uset[N]
=
{
0
}, acs[N], flag[N]
=
{
0
}, dis[N]
=
{
0
}, ans[N], visite[N]
=
{
0
};
int
find(
int
x ){
while
( x
!=
uset[x] ) x
=
uset[x];
return
x; }
void
join(
int
x,
int
y ){ uset[ find(x) ]
=
uset[ find(y) ]; }
void
dfs(
int
u,
int
d ){
uset[u]
=
u; acs[u]
=
u; dis[u]
=
d; visite[u]
=
1
;
for
( size_t i
=
0
; i
<
map[u].size();
++
i ){
int
v
=
map[u][i].first, w
=
map[u][i].second;
if
(
!
visite[v] ){
dfs( v, d
+
w );
join( u, v ); acs[ find(u) ]
=
u; }
}
flag[u]
=
1
;
for
( size_t i
=
0
; i
<
query[u].size();
++
i ){
int
v
=
query[u][i].first, w
=
query[u][i].second;
if
( flag[v] ) ans[w]
=
dis[u]
+
dis[v]
-
2
*
dis[ acs[ find(v) ] ];
}
}
int
main(){
int
u, v, d;
char
s[
10
];
scanf(
"
%d%d
"
,
&
n,
&
m);
while
( m
--
){
scanf(
"
%d%d%d%s
"
,
&
u,
&
v,
&
d,s );
map[u].push_back( PAIR(v,d) );
map[v].push_back( PAIR(u,d) );
}
scanf(
"
%d
"
,
&
m );
for
(
int
i
=
1
; i
<=
m;
++
i ){
scanf(
"
%d%d
"
,
&
u,
&
v );
query[u].push_back( PAIR(v,i) );
query[v].push_back( PAIR(u,i) );
}
memset( flag,
0
,
sizeof
(flag) );
memset( visite,
0
,
sizeof
(visite) );
dfs(
1
,
0
);
for
(
int
i
=
1
; i
<=
m;
++
i ) printf(
"
%d\n
"
, ans[i] );
return
0
;
}
posted on 2009-07-20 10:56
Darren 阅读(540)
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