Sightseeing Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1023 Accepted Submission(s): 444 Problem Description Tour operator Your Personal Holiday organises guided bus trips across the Ben
Marriage Match IV 题目链接: http://acm.hust.edu.cn/vjudge/contest/122685#problem/Q Description Do not sincere non-interference. Like that show, now starvae also take part in a show, but it take place between city A and B. Starvae is in city A and girls a
http://poj.org/problem?id=3463 Sightseeing Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 7252 Accepted: 2581 Description Tour operator Your Personal Holiday organises guided bus trips across the Benelux. Every day the bus moves from
POJ1741:Tree Time Limit: 1000MS Memory Limit: 30000K Total Submissions: 29574 Accepted: 9915 Description Give a tree with n vertices,each edge has a length(positive integer less than 1001). Define dist(u,v)=The min distance between node u and v.
Sightseeing Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 9247 Accepted: 3242 Description Tour operator Your Personal Holiday organises guided bus trips across the Benelux. Every day the bus moves from one city S to another city F. O
A Simple Chess Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 2597 Accepted Submission(s): 691 Problem Description There is a n×m board, a chess want to go to the position (n,m) from the pos
题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=3191 How Many Paths Are There Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2128 Accepted Submission(s): 749 Problem Description oooccc1 is
比如select gid from table group by gid 查询时使用下面的方法查询条数 select count(distinct gid) from table 使用select count(gid) from table group by gid是错误的 这样查询的是分组后 每个组内部的条数
分组后,统计记录条数: SELECT num,count(*) AS counts from test_a GROUP BY num; 查询结果如下: 对num去重后的数量的统计: SELECT count(t.counts) FROM ( SELECT num,count(*) AS counts from test_a GROUP BY num ) AS t; SELECT count(DISTINCT num) AS count FROM test_a; 它俩结果一样,都是5:只是一个是子
查询所有表名:select t.table_name from user_tables t;查询所有字段名:select t.column_name from user_col_comments t;查询指定表的所有字段名:select t.column_name from user_col_comments t where t.table_name = 'BIZ_DICT_XB';查询指定表的所有字段名和字段说明:select t.column_name, t.column_name from