關鍵字：求連續出現5次以上的值，並且取第5次所在id
關鍵字：求在某列連續出現n次值的的資料，並且取第m次出現所在行
需求，求連續出現5次以上的值，並且取第5次所在id
測試資料
create
table
temp1 (
id intprimary
keyidentity(1,1
), num1
int,
num2
int);
insert
into temp1 values( 11,51),( 12,52
);insert
into temp1 values( 10,101),( 10,102),( 10,103),( 10,104),( 10,105),( 10,106),( 10,107
);insert
into temp1 values( 13,53),( 14,54
);insert
into temp1 values( 10,108),( 10,109),( 10,110
);insert
into temp1 values( 15,55),( 16,56
);insert
into temp1 values( 10,111),( 10,112),( 10,113),( 10,114),( 10,115),( 10,116),( 10,117
);--
解決**（1）
;with t1 as
(
select
*,id-row_number() over(partition by num1 order
by id) x from
temp1
)select
*from
(
select*,
(count(1) over(partition by
x ) )
asy,
(row_number()
over(partition by x order
byid)
) asz
from
t1 a
) bwhere y>=
5and z=5（
2）;with t1 as
(
select
*,id - row_number() over(partition by num1 order
by id) x from
temp1
)select
*from
(
select*,
(select
count(1) from t1 where x=
a.x )
asy,
(select
count(1) from t1 where x=a.x and id <=
a.id
) asz
from
t1 a
) bwhere y>=
5and z=
5mysql
（1）臨時表方法select * from (create
table
test1 (
id intprimary
keyauto_increment,
num1
int,
num2
int);
insert
into test1 values(null,11,51),(null,12,52
);insert
into test1 values(null,10,101),(null,10,102),(null,10,103),(null,10,104),(null,10,105),(null,10,106),(null,10,107
);insert
into test1 values(null,13,53),(null,14,54
);insert
into test1 values(null,10,108),(null,10,109),(null,10,110
);insert
into test1 values(null,15,55),(null,16,56
);insert
into test1 values(null,10,111),(null,10,112),(null,10,113),(null,10,114),(null,10,115),(null,10,116),(null,10,117
);create
table test2 like
test1;
alter
table test2 change id id int
;alter
table test2 add rn int
unique
auto_increment;
insert
into test2(id,num1,num2) select
*from test1 where num1=10;
select
*,id-rn as x from
test2;
select
*from
(select*,
(select
count(1) from (select
*,id-rn as x from test2) t where t.x=
t1.x) y,
(select
count(1) from (select
*,id-rn as x from test2) t where t.x=t1.x and t.id <=
t1.id) z
from (select
*,id-rn as x from
test2) t1
) twhere y>=
5and z=
5（2）構造row_number()方法
select *,
(select count(1) from (select *,id-rn as x from (select test1.*, @num:=@num+1 as rn from test1 join (select @num:=0) temp1 where test1.num1=10) temp2) t where t.x=t1.x) y,
(select count(1) from (select *,id-rn as x from (select test1.*,@num1:=@num1+1 as rn from test1 join (select @num1:=0) temp1 where test1.num1=10) temp2 ) t where t.x=t1.x and t.id <= t1.id) z
from (select *,id-rn as x from (select test1.*,@num2:=@num2+1 as rn from test1 join (select @num2:=0) temp1 where test1.num1=10) temp2) t1
) twhere y>=5 and z=5
--再簡化
select * from (
select *,
(select count(1) from (select test1.*, id-@num:=@num+1 as x from test1 join (select @num:=0) temp1 where test1.num1=10) t where t.x=t1.x) y,
(select count(1) from (select test1.*,id-@num1:=@num1+1 as x from test1 join (select @num1:=0) temp1 where test1.num1=10) t where t.x=t1.x and t.id <= t1.id) z
from (select test1.*,id-@num2:=@num2+1 as x from test1 join (select @num2:=0) temp1 where test1.num1=10) t1
) twhere y>=5 and z=5
原表資料：結果：
連續出現k次的字元
描述 給定乙個字串，在字串中找到第乙個連續出現至少k次的字元。輸入第一行包含乙個正整數k，表示至少需要連續出現的次數。1 k 1000。第二行包含需要查詢的字串。字串長度在1到1000之間，且不包含任何空白符。輸出若存在連續出現至少k次的字元，輸出該字元 否則輸出no。樣例輸入 3 abcccaaa...
求連續子串行的最大值
問題描述 有一串數字 可正可負的int，放在陣列num裡 要求找到起始位置start和終止位置end，使得從start位置到end位置的所有數字之和最大，返回這個最大值max。演算法思想 使用動態規劃。設 f x 為以 a x 終止且包含 a x 的最大序列的和，有 f 1 a 1 f x 1 f ...
去掉字串連續出現的k次
移除字串中連續出現的k個0 可以用掃瞄字元陣列的解法，但是用正規表示式更為快捷 package 4字串 public class k去掉字串連續出現的k次 private static string zehengze string a,int k return a.replaceall regexp...