T******7
发帖数: 1419 | 1 1. 实现一个iterator，可以按照距离原点的曼哈顿距离输出所有的点。
曼哈顿距离iterator随便写了一个 请大家帮挑毛病，謝謝 | T******7
发帖数: 1419 | 2 import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.PriorityQueue;
public class ManhattanDistansIterator {
PriorityQueue pList = null;
int len;
int index;
public ManhattanDistansIterator(List points) {
len = points.size();
pList = new PriorityQueue<>(len, new Comparator() {
public int compare(Point p1, Point p2){
return (int) (Math.pow(p1.x, 2) + Math.pow(p2.x, 2) -
Math.pow(p2.x, 2) - Math.pow(p2.x, 2));
}
});
for(Point p : points){
pList.offer(p);
}
}
/** @return whether we have a next point */
public boolean hasNext() {
return (!pList.isEmpty());
}
/** @return the next nearest point */
public Point next() {
if(hasNext()){
return pList.poll();
} else {
return null;
}
}
public static void main(String[] args){
List pointList = new ArrayList<>();
Point p1 = new Point(1,4);
Point p2 = new Point(2,2);
Point p3 = new Point(0,1);
Point p4 = new Point(5,9);
pointList.add(p1);
pointList.add(p2);
pointList.add(p3);
pointList.add(p4);
ManhattanDistansIterator i = new ManhattanDistansIterator(
pointList);
while(i.hasNext()){
System.out.print(i.next());
}
}
}
class Point{
int x;
int y;
public Point(int x, int y){
this.x = x;
this.y = y;
}
public String toString(){
return "[" +x + "," + y + "] ";
}
}
/**
* Your BSTIterator will be called like this:
* BSTIterator i = new BSTIterator(root);
* while (i.hasNext()) v[f()] = i.next();
*/ | l****c
发帖数: 782 | 3 不能用额外space
【在 T******7 的大作中提到】
: 1. 实现一个iterator，可以按照距离原点的曼哈顿距离输出所有的点。
: 曼哈顿距离iterator随便写了一个 请大家帮挑毛病，謝謝
| m******3
发帖数: 346 | 4 不能用额外space是什么意思阿？楼主的程序里面用priority_queue算多余space么？如
果不用，怎么解呢？ |
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