我想为联盟中 20 支足球队的女孩随机分配球衣号码。
修复：我最终为每个团队使用 Collections.shuffle(shirtnums) 并处理顶部的数字。
这是我用来执行此操作的代码-
我有一个整数和一个 ArrayList：
int shirtnum = 0; ArrayList<Integer> shirtnums; shirtnums = new ArrayList<Integer>();在每个团队的开头，我将数字添加到其中：
for(int number = 1; number < 31; number++){shirtnums.add(number);}在每个团队结束时，我都会清除它：
shirtnums.clear();在 22 个女孩的循环中，我试图获取一个随机数，然后将其从 ArrayList 中删除：
double shirt = Math.floor(Math.random() * shirtnums.size()); shirtnum = (int) shirt; shirtnums.remove(shirtnum);
但是，这是一个团队的示例输出：
pid lname fname DOB posid tid shirtnum
1 Smith Mary 1997-09-05 1 1 23
2 Johnson Patricia 1997-04-03 2 1 15
3 Williams Linda 1998-03-03 3 1 10
4 Jones Barbara 1998-08-14 4 1 13
5 Brown Elizabeth 1998-02-24 5 1 13
6 Davis Jennifer 1998-08-27 6 1 12
7 Miller Maria 1997-09-06 7 1 2
8 Wilson Susan 1998-03-02 8 1 16
9 Moore Margaret 1997-01-04 9 1 2
10 Taylor Dorothy 1997-04-01 10 1 11
11 Anderson Lisa 1997-01-25 11 1 7
12 Thomas Nancy 1997-08-05 1 1 1
13 Jackson Karen 1997-01-18 2 1 8
14 White Betty 1997-01-16 3 1 5
15 Harris Helen 1998-06-12 4 1 7
16 Martin Sandra 1998-07-08 5 1 13
17 Thompson Donna 1997-10-11 6 1 11
18 Garcia Carol 1998-03-06 7 1 7
19 Martinez Ruth 1998-08-00 8 1 7
20 Robinson Sharon 1998-02-20 9 1 8
21 Clark Michelle 1997-00-00 10 1 2
22 Rodriguez Laura 1998-06-12 11 1 3
显然，我们不能让三个#13 和两个#2 在球场上跑来跑去……那我做错了什么？
根据要求，这是完整的代码：
import java.sql.*;
import java.lang.*;
import java.util.*;
public class GetSoccerNames
{
public static void main(String [] args)
{
//declare variables
Connection getconn = null;
Connection setconn = null;
Statement getstmt = null;
ResultSet names_rs = null;
String lastname = null;
String firstname = null;
double year = 0;
double month = 0;
double day = 0;
String DOB = null;
int posid = 0;
int tid = 1;
int shirtnum = 0;
int pid = 0;
ArrayList<Integer> shirtnums;
shirtnums = new ArrayList<Integer>();
try{
Class.forName("com.mysql.jdbc.Driver");
getconn = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/playernames", "root", "");
//setconn = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/league", "root", "");
getstmt = getconn.createStatement();
names_rs = getstmt.executeQuery("select fname, lname from names");
//for each team
for(tid = 1; tid < 4; tid++){
System.out.println("pid" + "\t" + "lname" + "\t" + "fname" + "\t" + "DOB" + "\t\t" + "posid" + "\t" + "tid" + "\t" + "shirtnum");
//int[] shirtnums = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30};
for(int number = 1; number < 31; number++){shirtnums.add(number);}
//for each player on the team
for(int teamplayer = 1; teamplayer < 23; teamplayer++){
//PID
// print i value ... remove for insert
pid++;
//NAME
names_rs.next();
lastname = names_rs.getString(2);
firstname = names_rs.getString(1);
//DOB
year = Math.round(Math.random() + (2013-16));
month = Math.round(Math.random() * 12);
day = Math.round(Math.random() * 28);
int yyyy = (int) year;
int mm = (int) month;
int dd = (int) day;
if (mm>9 && dd>9) {DOB = yyyy + "-" + mm + "-" + dd;}
else if (mm<10 && dd>9){DOB = yyyy + "-0" + mm + "-" + dd;}
else if (mm>9 && dd<10){DOB = yyyy + "-" + mm + "-0" + dd;}
else if (mm<10 && dd<10){DOB = yyyy + "-0" + mm + "-0" + dd;}
//POSID
posid = ((pid-1)%11)+1;
//TID
//tid is determined outside the loop
//SHIRTNUM
double shirt = Math.ceil(Math.random() * shirtnums.size());
shirtnum = (int) shirt;
shirtnums.remove(shirtnum - 1);
//TEST PRINT
System.out.println(pid + "\t" + lastname + "\t" + firstname + "\t" + DOB + "\t" + posid + "\t" + tid + "\t" + shirtnum);
}
shirtnums.clear();
}
}
catch(ClassNotFoundException cnfe){
System.out.println("Class Not Found: " + cnfe.getMessage());
}
catch(SQLException sqle){
System.out.println("SQL Error: " + sqle.getMessage());
}
finally{
if (getconn != null) try{getconn.close();} catch(SQLException ignore){}
if (getstmt != null) try{getstmt.close();} catch(SQLException ignore){}
if (names_rs != null) try{names_rs.close();} catch(SQLException ignore){}
}
}
}
我希望这会有所帮助。