diff --git "a/leetcode3/\353\202\250\355\232\250\354\240\225/3701. Compute Alternating Sum.py" "b/leetcode3/\353\202\250\355\232\250\354\240\225/3701. Compute Alternating Sum.py"
new file mode 100644
index 00000000..6546a2d0
--- /dev/null
+++ "b/leetcode3/\353\202\250\355\232\250\354\240\225/3701. Compute Alternating Sum.py"	
@@ -0,0 +1,11 @@
+class Solution:
+    def alternatingSum(self, nums: List[int]) -> int:
+        even, odd = 0, 0
+
+        for i in range(len(nums)):
+            if i % 2 == 0:
+                even += nums[i]
+            else:
+                odd += nums[i]
+        
+        return even - odd
\ No newline at end of file
diff --git "a/leetcode3/\353\202\250\355\232\250\354\240\225/785. Is Graph Bipartite.py" "b/leetcode3/\353\202\250\355\232\250\354\240\225/785. Is Graph Bipartite.py"
new file mode 100644
index 00000000..f962c325
--- /dev/null
+++ "b/leetcode3/\353\202\250\355\232\250\354\240\225/785. Is Graph Bipartite.py"	
@@ -0,0 +1,27 @@
+# 풀이 실패
+class Solution:
+    def isBipartite(self, graph: List[List[int]]) -> bool:
+        colors = {} # 노드별 색상
+
+        def dfs(node, color):
+            colors[node] = color
+
+            for neighbor in graph[node]:
+                # 인접한 노드가 같은 색상이면 실패
+                if neighbor in colors:
+                    if colors[neighbor] == color:
+                        return False
+                # 아직 색칠 안 된 노드면 재귀 호출
+                else:
+                    if not dfs(neighbor, -color):
+                        return False
+            return True
+
+        # 분리된 그래프 누락하지 않게 전부 순회
+        for i in range(len(graph)):
+            if i not in colors:
+                if not dfs(i, 1):
+                    return False
+
+        return True
+