diff --git a/Problem1.java b/Problem1.java
index e69de29b..1e950371 100644
--- a/Problem1.java
+++ b/Problem1.java
@@ -0,0 +1,57 @@
+import java.util.Arrays;
+
+// Bounded Knapsack
+public class Problem1 {
+
+    public static void main() {
+        int target = 4;
+        int[] weights = {4, 5, 1};
+        int[] profits = {1, 2, 3};
+
+        int max = knapsackTabulation(target, weights, profits); //
+        System.out.println(max);
+
+        max = knapsackRecursive(target, weights, profits, 0); //
+        System.out.println(max);
+    }
+
+
+    public static int knapsackTabulation(int target, int[] weights, int[] profits) {
+        // Time Complexity : O(N^2)
+        // Space Complexity : O(N^2)
+        int rows = weights.length + 1;
+        int cols = target + 1;
+
+        int[][] table = new int[rows][cols];
+        for (int i = 1; i < rows; i++) {
+            int currentWeight = weights[i - 1];
+            for (int j = 1; j < cols; j++) {
+                if (currentWeight <= j) {
+                    table[i][j] = profits[i - 1] + table[i - 1][j - currentWeight];
+                } else {
+                    table[i][j] = table[i - 1][j];
+                }
+            }
+        }
+
+        return table[rows - 1][cols - 1];
+    }
+
+    static int knapsackRecursive(int target, int[] weights, int[] profits, int index) {
+        // Time Complexity : O(2^N), where N is the number of weights, at every recursion, we need to make choice whether to include weight or exclude weight
+        // Space Complexity : O(N)
+        if (index >= weights.length) return 0;
+        if (target <= 0) return 0;
+
+        int choose = 0;
+        if (weights[index] <= target) {
+            // choose the item only once and move the index to next item
+            choose = profits[index] + knapsackRecursive(target - weights[index], weights, profits, index + 1);
+        }
+
+        int notChoose = knapsackRecursive(target, weights, profits, index + 1);
+
+        return Math.max(choose, notChoose);
+    }
+
+}
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diff --git a/Problem2.java b/Problem2.java
index e69de29b..dfbb1868 100644
--- a/Problem2.java
+++ b/Problem2.java
@@ -0,0 +1,23 @@
+import java.util.HashMap;
+import java.util.Map;
+
+public class Problem2{
+
+    public int[] twoSum(int[] nums, int target) {
+        // Time Complexity : O(N), N is number of elements in nums
+        // Space Complexity : O(N)
+        int [] result = new int[2];
+        Map<Integer, Integer> pairs = new HashMap<>();
+        for(int i = 0; i < nums.length; i++){
+            int complement = target - nums[i];
+            Integer index = pairs.getOrDefault(complement, null);
+            if( index == null){
+                pairs.put(nums[i], i);
+            }else {
+                result[0] = index;
+                result[1] = i;
+            }
+        }
+        return result;
+    }
+}
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