就是乱序一下嘛 import java.util.*;public class Test44 { public static void main(String[] args) { // TODO Auto-generated method stub Random rnd = new Random(); char[] arr = { 'a', 'b', 'c', 'd', 'e' }; for (int i = arr.length; i > 1; i--) swap(arr, i - 1, rnd.nextInt(i)); System.out.println(new String(arr)); } static void swap(char[] arr, int i, int j) { char tmp = arr[i]; arr[i] = arr[j]; arr[j] = tmp; } }要是犯懒,直接转List,然后用Collections的shuffle,一样的
import java.util.ArrayList;public class Atest2 { public static void main(String args[]){
ArrayList sList = new ArrayList(); sList.add("a"); sList.add("b"); sList.add("c"); sList.add("d"); sList.add("e"); int t = 5; String s =""; while(sList.size()>0){
double d = Math.random(); int i = (int)(d*t); s += (String)sList.get(i); sList.remove(i); t--;
} System.out.print(s);
} }ou shi cai niao~~~~
时间复杂度O(n), ...不懂..import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.util.Random; public class TestRandom { public static void main(String[] args){ List list = new ArrayList(); list.add("a"); list.add("b"); list.add("c"); list.add("d"); list.add("e"); System.out.println(list); Collections.shuffle(list,new Random()); System.out.println(list); } }
import java.util.*;public class Test44 { public static void main(String[] args) {
// TODO Auto-generated method stub
Random rnd = new Random();
char[] arr = { 'a', 'b', 'c', 'd', 'e' };
for (int i = arr.length; i > 1; i--)
swap(arr, i - 1, rnd.nextInt(i));
System.out.println(new String(arr));
} static void swap(char[] arr, int i, int j) {
char tmp = arr[i];
arr[i] = arr[j];
arr[j] = tmp;
}
}要是犯懒,直接转List,然后用Collections的shuffle,一样的
ArrayList sList = new ArrayList();
sList.add("a");
sList.add("b");
sList.add("c");
sList.add("d");
sList.add("e");
int t = 5;
String s ="";
while(sList.size()>0){
double d = Math.random();
int i = (int)(d*t);
s += (String)sList.get(i);
sList.remove(i);
t--;
}
System.out.print(s);
}
}ou shi cai niao~~~~
import java.util.Collections;
import java.util.List;
import java.util.Random;
public class TestRandom {
public static void main(String[] args){
List list = new ArrayList();
list.add("a");
list.add("b");
list.add("c");
list.add("d");
list.add("e");
System.out.println(list);
Collections.shuffle(list,new Random());
System.out.println(list);
}
}