来自XY坐标的Java字符串

Question

我有一个地图,Coords定义如下:

class Coords {
        int x;
        int y;
        public boolean equals(Object o) {
            Coords c = (Coords)o;
            return c.x==x && c.y==y;
        }
        public Coords(int x, int y) {
            super();
            this.x = x;
            this.y = y;
        }
        public int hashCode() {
            return new Integer(x+"0"+y);
        }
    }

(不是很好,我知道,请不要取笑我.)我现在如何创建一个字符串,从这个地图映射字符,例如:

Map<Coords, Character> map = new HashMap<Coords, Character>();
map.put(new Coords(0,0),'H');
map.put(new Coords(1,0),'e');
map.put(new Coords(2,0),'l');
map.put(new Coords(3,0),'l');
map.put(new Coords(4,0),'o');
map.put(new Coords(6,0),'!');
map put(new Coords(6,1),'!');
somehowTransformToString(map); //Hello !
                               //      !

谢谢,
Isaac Waller
(注意 - 这不是作业)

Answer 1

1. 创建一个比较器,可以用y和x对Coords进行排序:

   int d = c1.y - c2.y;
   if (d == 0) d = c1.x - c2.y;
   return d;
   

2. 创建有序地图:

   TreeMap<Coords, Character> sortedMap = new TreeMap(comparator);
   sortedMap.putAll(map); // copy values from other map
   

3. 按顺序打印地图的值:

   for (Character c: map.values()) System.out.print(c);
   

4. 如果您需要换行符:

   int y = -1;
   for (Map.Entry<Coords, Character> e: map.entrySet()) {
       if (e.y != y) {
           if (y != -1) System.out.println();
           y = e.y;
       }
       System.out.print(c);
   }