Merge pull request #362 from avnisinngh/Second_Add

Adding LeetCode Solutions
PRIYESHSINGH24 · Jan 20, 2025 · a482fd2 · a482fd2
2 parents a9d6507 + cb2b7f1
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diff --git a/LeetCode/39. Combination Sum.java b/LeetCode/39. Combination Sum.java
@@ -0,0 +1,28 @@
+import java.util.ArrayList;
+import java.util.List;
+
+class Solution {
+    public List<List<Integer>> combinationSum(int[] candidates, int target) {
+        List<List<Integer>> ans = new ArrayList<>();
+        List<Integer> ds = new ArrayList<>();
+        combination(candidates, target, 0, ans, ds);
+        return ans;
+    }
+    public void combination(int[] candidates, int target, int index, List<List<Integer>> ans, List<Integer> ds) {
+        //base case
+        if(index == candidates.length) {
+            if(target == 0) {
+                ans.add(new ArrayList<>(ds));
+            }
+            return ;
+        }
+        //pick
+        if(candidates[index] <= target) {
+            ds.add(candidates[index]);
+            combination(candidates, target - candidates[index], index, ans,ds);
+            ds.remove(ds.size()-1);
+        }
+        //not pick
+        combination(candidates, target, index+1, ans,ds);
+    }
+}
diff --git a/LeetCode/40. Combination Sum II.java b/LeetCode/40. Combination Sum II.java
@@ -0,0 +1,31 @@
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+class Solution {
+    public List<List<Integer>> combinationSum2(int[] candidates, int target) {
+        List<List<Integer>> ans = new ArrayList<>();
+        List<Integer> ds = new ArrayList<>();
+        Arrays.sort(candidates);
+        combination(candidates, target, ans, ds, 0);
+        return ans;
+    }
+    public void combination(int[] candidates, int target, List<List<Integer>> ans, List<Integer> ds, int index) {
+        //base case
+        if(target == 0) {
+            ans.add(new ArrayList<>(ds));
+            return ;
+        }
+        for(int i = index ; i < candidates.length; i++) {
+
+            //not pick
+            if(i > index && candidates[i] == candidates[i-1])   continue;
+            if(candidates[i] > target) break;
+
+            //pick 
+            ds.add(candidates[i]);
+            combination(candidates, target - candidates[i], ans, ds, i + 1);
+            ds.remove(ds.size() - 1);
+        }
+    }
+}