求编程 1-50,50个数,每次取双数,取出后继续取双数,求最后一个数是多少。如 12345 先取双 为 2 4 在取双为4,所以结果为4 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 public static ArrayList check(ArrayList al){ System.out.println(al.toString()); if(al.size()<=1)return al; ArrayList alist=new ArrayList(); for(int i=0;i<al.size();i++){ if((i+1)%2==0) alist.add(al.get(i)); } check(alist); return null;}结果:[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, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50][2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50][4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48][8, 16, 24, 32, 40, 48][16, 32, 48][32]用递归做的…… 楼上的很好写的 下面是我自己写的 呵呵 比较菜public class ArrayAdd { public static int[] add(int[] a){ int[] a2=new int[a.length/2]; for(int i=0;i<a.length;i++){ System.out.print(a[i]+" "); } System.out.println(""); if(a.length <=1){ return a; }else{ for(int i=0;i<a2.length;i++){ a2[i]=2*a[i]; } } add(a2); return a2; } public static void main(String[] args) { int[] array = new int[50]; for(int i=0;i<50;i++){ array[i]=i+1; } ArrayAdd.add(array); }} 着急啊 帮忙看看 求个功能的实现 一个spring_security的问题,解决了几天了!找高手解决。 选用什么MVC 转页 weblogic9.2 缓存文件的位置 如何解决用户显示(在线列表)问题 关于hibernate的奇怪性能问题 libhello.so: cannot dynamically load 100分求解:EJB部署出现的异常错误!!很奇怪!!! Java单点登录安全性怎么保障? IWAB0399E Error in generating Java from WSDL
public static ArrayList check(ArrayList al){
System.out.println(al.toString());
if(al.size()<=1)return al;
ArrayList alist=new ArrayList();
for(int i=0;i<al.size();i++){
if((i+1)%2==0)
alist.add(al.get(i));
}
check(alist);
return null;
}结果:
[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, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50]
[2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50]
[4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48]
[8, 16, 24, 32, 40, 48]
[16, 32, 48]
[32]
用递归做的……
public class ArrayAdd {
public static int[] add(int[] a){
int[] a2=new int[a.length/2];
for(int i=0;i<a.length;i++){
System.out.print(a[i]+" ");
}
System.out.println("");
if(a.length <=1){
return a;
}else{
for(int i=0;i<a2.length;i++){
a2[i]=2*a[i];
}
}
add(a2);
return a2;
}
public static void main(String[] args) {
int[] array = new int[50];
for(int i=0;i<50;i++){
array[i]=i+1;
}
ArrayAdd.add(array);
}
}