1.在找公共父节点的算法中新增一种思路2.完成了“求树中两个节点的最短路径”算法

最近公共父节点/最近公共父节点/main.cpp

@@ -19,8 +19,8 @@ struct TreeNode {
     }
 };
 
-// 找最近公共父节点
-TreeNode* findClosestParent(TreeNode *A, TreeNode *B, TreeNode *root) {
+// 找最近公共父节点（思路一）
+TreeNode* findClosestParent1(TreeNode *A, TreeNode *B, TreeNode *root) {
     if (root == NULL) {
         return NULL;
     }
@@ -29,8 +29,8 @@ TreeNode* findClosestParent(TreeNode *A, TreeNode *B, TreeNode *root) {
         return root;
     }
 
-    TreeNode *leftNode = findClosestParent(A, B, root->left);
-    TreeNode *rightNode = findClosestParent(A, B, root->right);
+    TreeNode *leftNode = findClosestParent1(A, B, root->left);
+    TreeNode *rightNode = findClosestParent1(A, B, root->right);
 
     if (leftNode != NULL && rightNode != NULL) {
         return root;
@@ -47,7 +47,33 @@ TreeNode* findClosestParent(TreeNode *A, TreeNode *B, TreeNode *root) {
     return NULL;
 }
 
-
+// 找最近公共父节点（思路二）
+TreeNode *findClosestParent2(TreeNode *A, TreeNode *B, TreeNode *root) {
+    if (root == NULL) {
+        return NULL;
+    }
+    TreeNode *currentLeft = findClosestParent1(A, B, root->left);
+    TreeNode *currentRight = findClosestParent1(A, B, root->right);
+    // 情况一：左右都为空
+    if (currentLeft == NULL && currentRight == NULL) {
+        // 1.1：root为目标节点
+        if (root == A || root == B) {
+            return root;
+            // 1.2：root不为目标节点
+        } else {
+            return NULL;
+        }
+        // 情况二：左边右边都不为空
+    } else if (currentLeft != NULL && currentRight != NULL) {
+        return root;
+        // 情况三：左边不为空，右边为空
+    } else if (currentLeft != NULL) {
+        return currentLeft;
+        // 情况四：左边为空，右边不为空
+    } else {
+        return currentRight;
+    }
+}
 
 int main(int argc, const char * argv[]) {
     // insert code here...

求树中两个节点的最短路径/求树中两个节点的最短路径.xcodeproj/project.pbxproj

@@ -0,0 +1,272 @@
+// !$*UTF8*$!
+{
+	archiveVersion = 1;
+	classes = {
+	};
+	objectVersion = 48;
+	objects = {
+
+/* Begin PBXBuildFile section */
+		6A49D541202061F400AB7E88 /* main.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 6A49D540202061F400AB7E88 /* main.cpp */; };
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+			dstPath = /usr/share/man/man1/;
+			dstSubfolderSpec = 0;
+			files = (
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+		};
+/* End PBXCopyFilesBuildPhase section */
+
+/* Begin PBXFileReference section */
+		6A49D53D202061F400AB7E88 /* 求树中两个节点的最短路径 */ = {isa = PBXFileReference; explicitFileType = "compiled.mach-o.executable"; includeInIndex = 0; path = "求树中两个节点的最短路径"; sourceTree = BUILT_PRODUCTS_DIR; };
+		6A49D540202061F400AB7E88 /* main.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = main.cpp; sourceTree = "<group>"; };
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+
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+			);
+			runOnlyForDeploymentPostprocessing = 0;
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+/* End PBXFrameworksBuildPhase section */
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+			isa = PBXGroup;
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+				6A49D53F202061F400AB7E88 /* 求树中两个节点的最短路径 */,
+				6A49D53E202061F400AB7E88 /* Products */,
+			);
+			sourceTree = "<group>";
+		};
+		6A49D53E202061F400AB7E88 /* Products */ = {
+			isa = PBXGroup;
+			children = (
+				6A49D53D202061F400AB7E88 /* 求树中两个节点的最短路径 */,
+			);
+			name = Products;
+			sourceTree = "<group>";
+		};
+		6A49D53F202061F400AB7E88 /* 求树中两个节点的最短路径 */ = {
+			isa = PBXGroup;
+			children = (
+				6A49D540202061F400AB7E88 /* main.cpp */,
+			);
+			path = "求树中两个节点的最短路径";
+			sourceTree = "<group>";
+		};
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+			buildPhases = (
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+				6A49D53A202061F400AB7E88 /* Frameworks */,
+				6A49D53B202061F400AB7E88 /* CopyFiles */,
+			);
+			buildRules = (
+			);
+			dependencies = (
+			);
+			name = "求树中两个节点的最短路径";
+			productName = "求树中两个节点的最短路径";
+			productReference = 6A49D53D202061F400AB7E88 /* 求树中两个节点的最短路径 */;
+			productType = "com.apple.product-type.tool";
+		};
+/* End PBXNativeTarget section */
+
+/* Begin PBXProject section */
+		6A49D535202061F400AB7E88 /* Project object */ = {
+			isa = PBXProject;
+			attributes = {
+				LastUpgradeCheck = 0920;
+				ORGANIZATIONNAME = meituan;
+				TargetAttributes = {
+					6A49D53C202061F400AB7E88 = {
+						CreatedOnToolsVersion = 9.2;
+						ProvisioningStyle = Automatic;
+					};
+				};
+			};
+			buildConfigurationList = 6A49D538202061F400AB7E88 /* Build configuration list for PBXProject "求树中两个节点的最短路径" */;
+			compatibilityVersion = "Xcode 8.0";
+			developmentRegion = en;
+			hasScannedForEncodings = 0;
+			knownRegions = (
+				en,
+			);
+			mainGroup = 6A49D534202061F400AB7E88;
+			productRefGroup = 6A49D53E202061F400AB7E88 /* Products */;
+			projectDirPath = "";
+			projectRoot = "";
+			targets = (
+				6A49D53C202061F400AB7E88 /* 求树中两个节点的最短路径 */,
+			);
+		};
+/* End PBXProject section */
+
+/* Begin PBXSourcesBuildPhase section */
+		6A49D539202061F400AB7E88 /* Sources */ = {
+			isa = PBXSourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+				6A49D541202061F400AB7E88 /* main.cpp in Sources */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
+/* End PBXSourcesBuildPhase section */
+
+/* Begin XCBuildConfiguration section */
+		6A49D542202061F400AB7E88 /* Debug */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				ALWAYS_SEARCH_USER_PATHS = NO;
+				CLANG_ANALYZER_NONNULL = YES;
+				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
+				CLANG_CXX_LIBRARY = "libc++";
+				CLANG_ENABLE_MODULES = YES;
+				CLANG_ENABLE_OBJC_ARC = YES;
+				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
+				CLANG_WARN_BOOL_CONVERSION = YES;
+				CLANG_WARN_COMMA = YES;
+				CLANG_WARN_CONSTANT_CONVERSION = YES;
+				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
+				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
+				CLANG_WARN_EMPTY_BODY = YES;
+				CLANG_WARN_ENUM_CONVERSION = YES;
+				CLANG_WARN_INFINITE_RECURSION = YES;
+				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
+				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
+				CLANG_WARN_STRICT_PROTOTYPES = YES;
+				CLANG_WARN_SUSPICIOUS_MOVE = YES;
+				CLANG_WARN_UNGUARDED_AVAILABILITY = YES_AGGRESSIVE;
+				CLANG_WARN_UNREACHABLE_CODE = YES;
+				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
+				CODE_SIGN_IDENTITY = "-";
+				COPY_PHASE_STRIP = NO;
+				DEBUG_INFORMATION_FORMAT = dwarf;
+				ENABLE_STRICT_OBJC_MSGSEND = YES;
+				ENABLE_TESTABILITY = YES;
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+				GCC_DYNAMIC_NO_PIC = NO;
+				GCC_NO_COMMON_BLOCKS = YES;
+				GCC_OPTIMIZATION_LEVEL = 0;
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"DEBUG=1",
+					"$(inherited)",
+				);
+				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
+				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
+				GCC_WARN_UNDECLARED_SELECTOR = YES;
+				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
+				GCC_WARN_UNUSED_FUNCTION = YES;
+				GCC_WARN_UNUSED_VARIABLE = YES;
+				MACOSX_DEPLOYMENT_TARGET = 10.13;
+				MTL_ENABLE_DEBUG_INFO = YES;
+				ONLY_ACTIVE_ARCH = YES;
+				SDKROOT = macosx;
+			};
+			name = Debug;
+		};
+		6A49D543202061F400AB7E88 /* Release */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				ALWAYS_SEARCH_USER_PATHS = NO;
+				CLANG_ANALYZER_NONNULL = YES;
+				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
+				CLANG_CXX_LIBRARY = "libc++";
+				CLANG_ENABLE_MODULES = YES;
+				CLANG_ENABLE_OBJC_ARC = YES;
+				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
+				CLANG_WARN_BOOL_CONVERSION = YES;
+				CLANG_WARN_COMMA = YES;
+				CLANG_WARN_CONSTANT_CONVERSION = YES;
+				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
+				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
+				CLANG_WARN_EMPTY_BODY = YES;
+				CLANG_WARN_ENUM_CONVERSION = YES;
+				CLANG_WARN_INFINITE_RECURSION = YES;
+				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
+				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
+				CLANG_WARN_STRICT_PROTOTYPES = YES;
+				CLANG_WARN_SUSPICIOUS_MOVE = YES;
+				CLANG_WARN_UNGUARDED_AVAILABILITY = YES_AGGRESSIVE;
+				CLANG_WARN_UNREACHABLE_CODE = YES;
+				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
+				CODE_SIGN_IDENTITY = "-";
+				COPY_PHASE_STRIP = NO;
+				DEBUG_INFORMATION_FORMAT = "dwarf-with-dsym";
+				ENABLE_NS_ASSERTIONS = NO;
+				ENABLE_STRICT_OBJC_MSGSEND = YES;
+				GCC_C_LANGUAGE_STANDARD = gnu11;
+				GCC_NO_COMMON_BLOCKS = YES;
+				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
+				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
+				GCC_WARN_UNDECLARED_SELECTOR = YES;
+				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
+				GCC_WARN_UNUSED_FUNCTION = YES;
+				GCC_WARN_UNUSED_VARIABLE = YES;
+				MACOSX_DEPLOYMENT_TARGET = 10.13;
+				MTL_ENABLE_DEBUG_INFO = NO;
+				SDKROOT = macosx;
+			};
+			name = Release;
+		};
+		6A49D545202061F400AB7E88 /* Debug */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				CODE_SIGN_STYLE = Automatic;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+			};
+			name = Debug;
+		};
+		6A49D546202061F400AB7E88 /* Release */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				CODE_SIGN_STYLE = Automatic;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+			};
+			name = Release;
+		};
+/* End XCBuildConfiguration section */
+
+/* Begin XCConfigurationList section */
+		6A49D538202061F400AB7E88 /* Build configuration list for PBXProject "求树中两个节点的最短路径" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				6A49D542202061F400AB7E88 /* Debug */,
+				6A49D543202061F400AB7E88 /* Release */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
+		6A49D544202061F400AB7E88 /* Build configuration list for PBXNativeTarget "求树中两个节点的最短路径" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				6A49D545202061F400AB7E88 /* Debug */,
+				6A49D546202061F400AB7E88 /* Release */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
+/* End XCConfigurationList section */
+	};
+	rootObject = 6A49D535202061F400AB7E88 /* Project object */;
+}

求树中两个节点的最短路径/求树中两个节点的最短路径.xcodeproj/xcuserdata/nineteen.xcuserdatad/xcschemes/xcschememanagement.plist

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>SchemeUserState</key>
+	<dict>
+		<key>求树中两个节点的最短路径.xcscheme</key>
+		<dict>
+			<key>orderHint</key>
+			<integer>0</integer>
+		</dict>
+	</dict>
+</dict>
+</plist>