找到和为某个数的组合

src/main/java/com/neotel/smfcore/custom/luxsan/factory_c/wipstor/util/ManualWorkUtil.java

 package com.neotel.smfcore.custom.luxsan.factory_c.wipstor.util;
 
+import cn.hutool.core.util.RandomUtil;
+import com.google.common.collect.Lists;
 import com.neotel.smfcore.core.device.util.DataCache;
 import com.neotel.smfcore.custom.luxsan.factory_c.common.util.CacheNameUtil;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 @Component
 public class ManualWorkUtil {
@@ -38,4 +37,41 @@ public class ManualWorkUtil {
         return cacheMap.containsKey(boxStr);
     }
 
+
+    public static void findCombinations(List<Integer> numbers, int target) {
+        // 使用HashMap来存储和值及其对应的组合次数
+        Map<Integer, List<Integer>> sumCounts = new HashMap<>();
+        sumCounts.put(0, new ArrayList<>()); // 初始化，和为0的组合有1种（即不选任何数）
+
+        for (int num : numbers) {
+            Map<Integer, List<Integer>> temp = new HashMap<>(sumCounts); // 复制当前的和值映射，避免在迭代过程中修改
+            for (Map.Entry<Integer, List<Integer>> entry : temp.entrySet()) {
+                int sum = entry.getKey();
+                Integer newSum = sum + num;
+                if (newSum <= target) { // 只考虑不超过target的和
+                    List<Integer> oldValue = new ArrayList<>(entry.getValue());
+                    if(!sumCounts.containsKey(newSum)){
+                        oldValue.add(num);
+                        sumCounts.put(newSum,oldValue);
+                        if(newSum == target){
+                            System.out.println("找到和为 " + target + " 的组合为 " + oldValue +" 共:" + oldValue.size());
+                            return;
+                        }
+                    }
+                }
+            }
+        }
+
+        System.out.println(sumCounts.size());
+    }
+
+    public static void main(String[] args) {
+        List<Integer> numbers = new ArrayList<>();
+        for (int i = 0; i < 100; i++) {
+            numbers.add(1);
+        }
+        int target = 101;
+        findCombinations(numbers, target);
+    }
+
 }