更新背包基础理论01背包-1， 增加Java代码

problems/背包理论基础01背包-1.md

@@ -265,9 +265,46 @@ int main() {
 
 ## 其他语言版本
 
-
 Java：
 
+```java
+		public static void main(String[] args) {
+        int[] weight = {1, 3, 4};
+        int[] value = {15, 20, 30};
+        int bagSize = 4;
+        testWeightBagProblem(weight, value, bagSize);
+    }
+
+    public static void testWeightBagProblem(int[] weight, int[] value, int bagSize){
+        int wLen = weight.length, value0 = 0;
+        //定义dp数组：dp[i][j]表示背包容量为j时，前i个物品能获得的最大价值
+        int[][] dp = new int[wLen + 1][bagSize + 1];
+        //初始化：背包容量为0时，能获得的价值都为0
+        for (int i = 0; i <= wLen; i++){
+            dp[i][0] = value0;
+        }
+        //遍历顺序：先遍历物品，再遍历背包容量
+        for (int i = 1; i <= wLen; i++){
+            for (int j = 1; j <= bagSize; j++){
+                if (j < weight[i - 1]){
+                    dp[i][j] = dp[i - 1][j];
+                }else{
+                    dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - weight[i - 1]] + value[i - 1]);
+                }
+            }
+        }
+        //打印dp数组
+        for (int i = 0; i <= wLen; i++){
+            for (int j = 0; j <= bagSize; j++){
+                System.out.print(dp[i][j] + " ");
+            }
+            System.out.print("\n");
+        }
+    }
+```
+
+
+
 
 Python：