一、PHP 基础部分
1》 获取文件名
function get_ext1($file_name){
return strrchr($file_name, '.');
}
function get_ext2($file_name){
return substr($file_name, strrpos($file_name, '.'));
}
function get_ext3($file_name){
return array_pop(explode('.', $file_name));
}
function get_ext4($file_name){
return pathinfo($file_name, PATHINFO_EXTENSION);
}
function get_ext5($file_name){
return strrev(substr(strrev($file_name), 0, strpos(strrev($file_name), '.')));
}
echo get_ext1('/tp5/app/controller/d.class.php');
2》获取url 扩展名
3》字符串'open_door' 转换成'OpenDoor'、'make_by_id' 转换成 'MakeById'。
function str_explode($str){
$str_arr=explode('_',$str);
$str_implode=implode('',$str_arr);
$str_implode=implode('',explode('',ucwords($str_implode)));
return $str_implode;
}
$strexplode=str_explode('make_by_id');
print_r($strexplode);
方法二:
$str='make_by_id!';
$expStr=explode('_',$str);
for($i=0;$i<count($expStr);$i++)
{
echo ucwords($expStr[$i]);
}
方法三:
echo str_replace(' ','',ucwords(str_replace('_',' ','open_door')))
4》unset()
$test = 'aaaaaa';
$abc = & $test;
unset($test);
echo $abc; aaaaaa
二、知识点部分
1》MySQL数据库中的字段类型varchar和char的主要区别是什么?那种字段的查找效率要高,为什么?
Varchar是变长,节省存储空间,char是固定长度。查找效率要char型快,因为varchar是非定长,必须先查找长度,然后进行数据的提取,比char定长类型多了一个步骤,所以效率低一些
三、排序部分
1》冒泡排序
function bubble_sort($array){
$count = count($array);
if ($count <= 0) return false;
for($i=0; $i<$count; $i++){
for($j=$i; $j<$count-1; $j++){
if ($array[$i] > $array[$j]){
$tmp = $array[$i];
$array[$i] = $array[$j];
$array[$j] = $tmp;
}
}
}
return $array;
}
2》快速排序
function quick_sort($array) {
if (count($array) <= 1) return $array;
$key = $array[0];
$left_arr = array();
$right_arr = array();
for ($i=1; $i<count($array); $i++){
if ($array[$i] <= $key)
$left_arr[] = $array[$i];
else
$right_arr[] = $array[$i];
}
$left_arr = quick_sort($left_arr);
$right_arr = quick_sort($right_arr);
return array_merge($left_arr, array($key), $right_arr);
}
3》二分查找排序
function A($arr, $target) { //定义开始和结束的下标 $start = 0; $end = count($arr) - 1; //循环 while($start <= $end) { //取中间值 $mid = floor(($start + $end) / 2); if($arr[$mid] == $target) { return $mid; } //查询的数小,往左继续查找 if($arr[$mid] > $target) { $end = $mid - 1; } //查询的数大,往右继续查找 if($arr[$mid] < $target) { $start = $mid + 1; } } } echo A($arr, 11);
4》顺序查找排序
function seq_sch($array, $n, $k){
$array[$n] = $k;
for($i=0; $i<$n; $i++){
if($array[$i]==$k){
break;
}
}
if ($i<$n){
return $i;
}else{
return -1;
}
}
5》二维数组排序
function array_sort($arr, $keys, $order=0) {
if (!is_array($arr)) {
return false;
}
$keysvalue = array();
foreach($arr as $key => $val) {
$keysvalue[$key] = $val[$keys];
}
if($order == 0){
asort($keysvalue);
}else {
arsort($keysvalue);
}
reset($keysvalue);
foreach($keysvalue as $key => $vals) {
$keysort[$key] = $key;
}
$new_array = array();
foreach($keysort as $key => $val) {
$new_array[$key] = $arr[$val];
}
return $new_array;
}
四、sql 部分
1》查询每门课都大于80分的同学的姓名:
select distinct name from grade where name not in (select distinct name from grade where score<=80);
或:
select name from grade group by name having min(score)>80;
2》平均分
select name from ( select count(*) t, sum(score) num, name from grade group by name ) as a where a.num>80*t;
或;
select name, avg(score) as sc from grade group by name having avg(score)>80;
3》 该标题内容为转载:https://www.cnblogs.com/cheng88/p/10585715.html
MySQL45道面试题及答案
create database school; use school; #学生表 create table `Student` ( `Sno` varchar(20) not null COMMENT '人名', `Sname` varchar(20) not null COMMENT '姓名', `Ssex` varchar(20) not null COMMENT '性别', `Sbirthday` datetime COMMENT '出生日期', `Class` varchar(20) COMMENT '班级' ); #课程表 create table `Course`( `Cno` varchar(20) not null COMMENT '课程号', `Cname` varchar(20) not null COMMENT '课程名称', `Tno` varchar(20) not null COMMENT '教工编号' ); #成绩表 Create table `Score` ( `Sno` varchar(20) not null COMMENT '学号', `Cno` varchar(20) not NULL comment '课程号', `Degree` DECIMAL(4,1) null COMMENT '成绩' ); #教师表 create table `Teacher` ( `Tno` varchar(20) not null COMMENT '教工编号', `Tname` varchar(20) not null COMMENT '教工姓名', `Tsex` varchar(20) not null COMMENT '教工性别', `Tbirthday` datetime null COMMENT '教工出生日期', `Prof` varchar(20) null COMMENT '职称', `Depart` varchar(20) null COMMENT '教工所在部门' ); insert into `Student` value (108,'曾华','男','1977-09-01',95033), (105,'匡明','男','1975-10-02',95031), (107,'王丽','女','1976-01-23',95033), (101,'李军','男','1976-02-20',95033), (109,'王芳','女','1975-02-10',95031), (103,'陆军','男','1974-06-03',95031); insert into `Course` value (3-105,'计算机导论',825), (3-245,'操作系统',804), (6-166,'数字电路',856), (9-888,'高等数学',831); insert into `Score` value (103,3-245,86), (105,3-245,75), (109,3-245,68), (103,3-105,92), (105,3-105,88), (109,3-105,76), (101,2-105,64), (107,3-105,91), (108,3-105,78), (101,6-166,85), (107,6-166,79), (108,6-166,81); insert into `Teacher` value (804,'李城','男','1958-12-02','副教授','计算机系'), (856,'张旭','男','1969-03-12','讲师','电子工程系'), (825,'王萍','女','1972-05-05','助教','计算机系'), (831,'刘冰','女','1977-08-14','助教','电子工程系'); #1、 查询Student表中的所有记录的Sname、Ssex和Class列。 select `Sname`,`Ssex`,`Class` from `Student`; #2、 查询教师所有的单位即不重复的Depart列。(多练) select distinct Depart from `Teacher`; -- 第三题 查询Student表的所有记录。 select * from `Student`; -- 第四题 查询Score表中成绩在60到80之间的所有记录。 select * from `Score` where Degree >60 and Degree<80; select * from `Score` where Degree between 60 and 80; -- 第五题 查询Score表中成绩为85,86或88的记录。 select * from `Score` where Degree = 85 or Degree = 86 or Degree = 88; select * from `Score` where Degree in(85,86,88); -- 第六题 查询Student表中“95031”班或性别为“女”的同学记录。 select * from `Student` where Class = '95031' or Ssex ='女'; -- 第七题 以Class降序查询Student表的所有记录。 select * from `Student` order by Class desc; -- 第八题 以Cno升序、Degree降序查询Score表的所有记录。 select * from `Score` order by Cno asc,Degree desc ; -- 第九题 查询“95031”班的学生人数。 select count(*) from `Student` where Class = '95031'; -- 第十题 查询Score表中的最高分的学生学号和课程号。(子查询或者排序) select Sno,Cno from `Score` where Degree=(select Max(Degree) from Score); select Sno,Cno from `Score` order by Degree desc; -- 第十一题 查询每门课的平均成绩。(group by:根据Cno进行分组) select Cno,AVG(Degree) as 平均分 from `Score` group by Cno; -- 第十二题 查询Score表中至少有5名学生选修的并以3开头的课程的平均分数。 select * from `Score` where Cno like '3%' group by Cno having Count(Cno)>4; -- 第十三题 查询分数大于70,小于90的Sno列。 select Sno from `Score` where Degree>70 or Degree<90; select Sno from `Score` where Degree between 70 and 90; -- 第十四题 查询所有学生的Sname、Cno和Degree列。 select Sname,Cno from `Student` join `Score` on `Student`.Sno = `Score`.Sno; -- 第十五题 查询所有学生的Sno、Cname和Degree列。 select Sno,Cname,Degree from Score join Course on Course.Cno = Score.Cno; -- 第十六题 查询所有学生的Sname、Cname和Degree列。 select Sname,Cname,Degree from `Student` join Score on `Student`.Sno = `Score`.Sno join Course on `Course`.Cno = `Score`.Sno; -- 第十七题 查询“95033”班学生的平均分。(子查询or条件查询) select AVG(Degree) from `Score` where Sno in(select Sno from `Student` where Class='95033'); select Avg(Degree) from `Score`,Student where Student.Sno = Score.Sno and Class = '95033'; -- 第十八题 假设使用如下命令建立了一个grade表: create table `grede`( `low` int COMMENT '人名', `upp` int not null COMMENT '课长', `rank` varchar(20) not null COMMENT '等级' ); insert into `grede` values(90,100,'A'); insert into `grede` values(80,89,'B'); insert into `grede` values(70,79,'C'); insert into `grede` values(60,69,'D'); insert into `grede` values(0,59,'E'); -- 现查询所有同学的Sno、Cno和rank列。(between选取两个值之间的数据范围) select Sno,Cno,Degree,rank from grede join Score on Score.Degree between low and upp; select Sno,Cno,Degree,rank from Score,grede where Degree between low and upp; -- 第十九题 查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录。 select * from Student,Score where Score.Cno = '3-105' and Student.Sno = Score.Sno and Score.Degree>(select Degree from Score where Cno = '3-105' and Sno = '109'); -- 第二十题 查询score中选学多门课程的同学中分数为非最高分成绩的记录。 select * from Score a where Degree<(select MAX(Degree)from Score b where a.Cno = b.Cno) and Sno in(select Sno from Score group by Sno having count(*) > 1); -- 第二十一题 查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。 select * from Student,Score where Student.Sno = Score.Sno and Score.Degree> (select Degree from Score where Cno='3-105' and Sno = '109'); -- 第二十二题 查询和学号为107的同学同年出生的所有学生的Sno、Sname和Sbirthday列。 select Sno,Sname,Sbirthday from student where year(Student.Sbirthday) = ( select year(Sbirthday) from student where Sno = '107' ); -- 第二十三题 查询“张旭“教师任课的学生成绩 select Sno,Cno,Degree from Score where Cno in(select Cno from Course where Tno in(select Tno from Teacher where Tname = '张旭')); -- 第二十四题 查询选修某课程的同学人数多于5人的教师姓名。 select Tname from Teacher where Tno in(select Tno from Course where Cno in(select Cno from Score group by Cno having Count(*)>5)); -- 第二十五题 查询95033班和95031班全体学生的记录。 select * from Student where Class = '95033' or Class = '95031'; -- 第二十六题 查询存在有85分以上成绩的课程Cno. select distinct cno from Score where Degree>85; -- 第二十七题 查询出“计算机系“教师所教课程的成绩表。 select Sno,Cno,Degree from Score where Cno in(select Cno from Course where Tno in( select tno from Teacher where Depart = '计算机系' )); -- 第二十八题查询“计算机系”与“电子工程系“不同职称的教师的Tname和Prof。使用相关子查询 select Tname,Prof from Teacher a where Prof not in(select Prof from Teacher b where a.Depart!=b.Depart); -- 第二十九题 查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”课程的同学的Cno、Sno和Degree,并按Degree从高到低次序排序。 select Cno,Sno,Degree from Score a where (select Degree from Score b where Cno='3-105' and b.Sno = a.Sno)>=(select Degree from Score c where Cno='3-245' and c.Sno = a.Sno)order by Degree desc ; -- 第三十题 查询选修编号为“3-105”课程且成绩高于选修编号为“3-245”课程的同学的Cno、Sno和Degree. select Cno,Sno,Degree from Score a where (select Degree from Score b where Cno='3-105' and b.Sno=a.Sno)>(select Degree from Score c where Cno='3-245' and c.Sno=a.Sno); -- 第三十一题 查询所有教师和同学的name、sex和birthday. select distinct Sname as name,Ssex as sex,Sbirthday as birthday from student union select distinct Tname as name,Tsex as sex,Tbirthday as birthday from Teacher; -- 第三十二题 查询所有“女”教师和“女”同学的name、sex和birthday. select distinct Sname as name,Ssex as sex,Sbirthday as birthday from student where Ssex = '女' union select distinct Tname as name,Tsex as sex,Tbirthday as birthday from Teacher where Tsex = '女'; -- 第三十三题 查询成绩比该课程平均成绩低的同学的成绩表。 select Sno,Cno,Degree from Score a where a.Degree<(select AVG(Degree) from Score b where a.Cno = b.Cno); -- 第三十四题 查询所有任课教师的Tname和Depart. select Tname,Depart from Teacher where Tname in(select distinct Tname from Teacher, Course,Score where Teacher.Tno = Course.Tno and Course.Cno = Score.Cno); select Tname,Depart from Teacher where tno in (select tno from course where Cno in (select distinct Cno from Score)); -- 第三十五题 查询所有未讲课的教师的Tname和Depart. select Tname,Depart from Teacher where Tname not in(select distinct Tname from Teacher,Course,Score where Teacher.Tno=Course.Tno and Course.Cno = Score.Cno); -- 第三十六题 查询至少有2名男生的班号。 select Class from student where Ssex='男' group by Class having count(*)>1; -- 第三十七题 查询Student表中不姓“王”的同学记录。 select * from Student where Sname not like ('王%'); -- 第三十八题 查询Student表中每个学生的姓名和年龄。 select Sname,YEAR(GETDATE())-year(Sbirthday) from student; -- 第三十九题 查询Student表中最大和最小的Sbirthday日期值 select MAX(Sbirthday) as 最大,MIN(Sbirthday) as 最小 from student; -- 第四十题 以班号和年龄从大到小的顺序查询Student表中的全部记录 select * from Student order by Class desc ,Sbirthday asc; -- 第四十一题 查询“男”教师及其所上的课程。 select Tname,Cname from Teacher,Course where Tsex='男' and Teacher.Tno = Course.Tno; -- 第四十二题 查询最高分同学的Sno、Cno和Degree列。 select Sno,Cno,Degree from Score where Degree=(select MAX(Degree) FROM score); -- 第四十三题 查询和“李军”同性别的所有同学的Sname. select SName from Student where Ssex=(select Ssex from Student where Sname='李军')and Sname not in ('李军'); -- 第四十四题 查询和“李军”同性别并同班的同学Sname select Sname from Student where Ssex=(select Ssex from Student where Sname='李军')and Sname not in ('李军')and Class=(select Class from Student where Sname='李军'); -- 第四十五题 查询所有选修“计算机导论”课程的“男”同学的成绩表 select Sno,Degree from Score where Sno in(select Sno from Student where Ssex='男')and Cno in (select Cno from Course where Cname='计算机导论');
五、linux 部分
六、逻辑题(图)
PHP实现螺旋矩阵(螺旋数组)
转载:https://www.cnblogs.com/chenqionghe/p/4765802.html
function
rotationSort(
$row
=5,
$col
=5)
{
$k
=1;
$result
=
array
();
$small
=
$col
<
$row
?
$col
:
$row
;
$count
=
ceil
(
$small
/ 2);
for
(
$i
=0;
$i
<
$count
;
$i
++)
{
$maxRight
=
$col
-1-
$i
;
//右边最大坐标
$maxBottom
=
$row
-1 -
$i
;
//下面最大坐标
for
(
$j
=
$i
;
$j
<=
$maxRight
;
$j
++)
//构造上边一条线 纵坐标最小,横坐标递增
{
$result
[
$i
][
$j
] =
$k
++;
}
for
(
$j
=
$i
;
$j
<
$maxBottom
;
$j
++)
//构造右边一条线 纵坐标递增,横坐标最大
{
$result
[
$j
+1][
$maxRight
] =
$k
++;
}
for
(
$j
=
$maxRight
-1;
$j
>=
$i
;
$j
--)
//构造下边一条线 纵坐标最大,横坐标递减
{
if
(
$result
[
$maxBottom
][
$j
])
break
;
$result
[
$maxBottom
][
$j
] =
$k
++;
}
for
(
$j
=
$maxBottom
-1;
$j
>
$i
;
$j
--)
//构造左边一条线 纵坐标递减,横坐标最小
{
if
(
$result
[
$j
][
$i
])
break
;
$result
[
$j
][
$i
] =
$k
++;
}
}
return
$result
;
}
|
$row
= 5;
$col
= 5;
$arr
= rotationSort(
$row
,
$col
);
printArray(
$arr
,
$row
,
$col
);
2,
|