2025-01-25 贪心算法-电台问题

src/dataANDcalc/java/algorithm/Greedy.java

@@ -0,0 +1,83 @@
+package algorithm;
+
+import java.util.*;
+
+public class Greedy {
+
+    private HashMap<String, List<String>> radios = new HashMap<>();
+
+    private HashSet<String> areas = new HashSet<>();
+
+    private List<String> selectRadios = new ArrayList<>();
+
+
+    private void allArea(){
+        for(Map.Entry<String, List<String>> entry : radios.entrySet()){
+            areas.addAll(entry.getValue());
+        }
+    }
+
+    private void greedySelectRadio(){
+        while(areas.size() > 0){
+            String maxKey = "";
+            int coverSize = 0;
+            for(Map.Entry<String, List<String>> entry : radios.entrySet()){
+                int currentCoverSize = 0;
+                List<String> values = entry.getValue();
+                for(String value : values){
+                    if(areas.contains(value)){
+                        currentCoverSize ++;
+                    }
+                }
+                if(currentCoverSize > coverSize){
+                    maxKey = entry.getKey();
+                    coverSize = currentCoverSize;
+                }
+            }
+            selectRadios.add(maxKey);
+            List<String> selects = radios.get(maxKey);
+            for(String select : selects){
+                areas.remove(select);
+            }
+        }
+    }
+
+    private void showSelectRadio(){
+        System.out.println("选择的电台:");
+        for(String radio : selectRadios){
+            System.out.println(radio);
+        }
+    }
+
+
+    public static void main(String[] args) {
+        Greedy greedy = new Greedy();
+        List<String> K1 = new ArrayList<>();
+        K1.add("北京");
+        K1.add("上海");
+        K1.add("天津");
+        greedy.radios.put("K1", K1);
+        List<String> K2  = new ArrayList<>();
+        K2.add("北京");
+        K2.add("广州");
+        K2.add("深圳");
+        greedy.radios.put("K2", K2);
+        List<String> K3  = new ArrayList<>();
+        K3.add("成都");
+        K3.add("上海");
+        K3.add("杭州");
+        greedy.radios.put("K3", K3);
+        List<String> K4  = new ArrayList<>();
+        K4.add("上海");
+        K4.add("天津");
+        greedy.radios.put("K4", K4);
+        List<String> K5  = new ArrayList<>();
+        K5.add("杭州");
+        K5.add("大连");
+        greedy.radios.put("K5", K5);
+        greedy.allArea();
+        greedy.greedySelectRadio();
+        greedy.showSelectRadio();
+    }
+
+}