POJ 2528 Mayor's posters
/*
按照大牛博客顺序做的题目
以前离散化好好理解了下
注意离散化后
struct SegTree{
int l, r;
int color;
int getMid(){
return (l + r) >> 1;
}
}tree[MAXN << 2];
中l，r不是原区间的坐标了，而是排序去重后数组中对应的下标
做这题问题不大 基本上1A 第一次数组开小了 囧.
*/
#include
<
stdio.h
>
#include
<
stdlib.h
>
#include
<
string
.h
>
#define
L(x) ((x) << 1)
#define
R(x) ((x) << 1 | 1)
#define
MAXN 100100
struct
SegTree{
int
l, r;
int
color;
int
getMid(){
return
(l
+
r)
>>
1
;
}
}tree[MAXN
<<
2
];
struct
Query{
//
询问区间的数据结构
int
left, right;
}q[
10010
];
bool
hash[
10010
];
//
统计颜色用的
int
bin[
20020
];
int
cmp(
const
void
*
a,
const
void
*
b){
return
*
(
int
*
)a
-
*
(
int
*
)b;
}
int
bs(
int
left,
int
right,
int
tar){
//
二分查找区间坐标在bin中的位置
while
(left
<=
right){
int
mid
=
(left
+
right)
>>
1
;
if
(bin[mid]
==
tar)
return
mid;
if
(bin[mid]
>
tar)
right
=
mid
-
1
;
else
left
=
mid
+
1
;
}
}
void
bulid(
int
left,
int
right,
int
t){
tree[t].l
=
left;
tree[t].r
=
right;
tree[t].color
=
0
;
if
(left
==
right)
return
;
int
mid
=
tree[t].getMid();
bulid(left, mid, L(t));
bulid(mid
+
1
, right, R(t));
}
void
insert(
int
left,
int
right,
int
color,
int
t){
if
(left
<=
tree[t].l
&&
right
>=
tree[t].r){
tree[t].color
=
color;
return
;
}
if
(tree[t].color
!=
-
1
){
tree[L(t)].color
=
tree[R(t)].color
=
tree[t].color;
tree[t].color
=
-
1
;
}
int
mid
=
tree[t].getMid();
if
( right
<=
mid ){
insert(left, right, color, L(t));
}
else
if
( left
>
mid ){
insert(left, right, color, R(t));
}
else
{
insert(left, mid, color, L(t));
insert(mid
+
1
, right, color, R(t));
}
if
(tree[L(t)].color
==
tree[R(t)].color
&&
tree[L(t)].color
!=
-
1
){
tree[t].color
=
tree[L(t)].color;
}
}
int
query(
int
t){
if
( tree[t].l
==
tree[t].r ){
if
( tree[t].color
!=
-
1
){
if
(
!
hash[tree[t].color] ){
hash[tree[t].color]
=
true
;
return
1
;
}
else
return
0
;
}
}
if
( tree[t].color
!=
-
1
){
if
(
!
hash[tree[t].color] ){
hash[tree[t].color]
=
true
;
return
1
;
}
else
{
return
0
;
}
}
return
query(L(t))
+
query(R(t));
}
int
main(){
int
t, n;
scanf(
"
%d
"
,
&
t);
while
( t
--
){
int
num
=
1
;
scanf(
"
%d
"
,
&
n);
for
(
int
i
=
1
; i
<=
n;
++
i){
scanf(
"
%d%d
"
,
&
q[i].left,
&
q[i].right);
bin[num
++
]
=
q[i].left;
bin[num
++
]
=
q[i].right;
}
//
升序排序
qsort(bin
+
1
, num
-
1
,
sizeof
(bin[
0
]), cmp);
//
bin从1开始 个数num-1个
//
去重
int
cnt
=
1
;
for
(
int
i
=
2
; i
<
num;
++
i){
if
(bin[i]
!=
bin[i
-
1
])
bin[
++
cnt]
=
bin[i];
}
bulid(
1
, cnt,
1
);
for
(
int
i
=
1
; i
<=
n;
++
i){
int
l
=
bs(
1
, cnt, q[i].left);
int
r
=
bs(
1
, cnt, q[i].right);
insert(l, r, i,
1
);
}
memset(hash,
false
,
sizeof
(hash));
hash[
0
]
=
true
;
printf(
"
%d\n
"
,query(
1
));
}
return
0
;
}