154 {

155 BiTree tar;

156

157 tar = Search(*T, p->data);

158 if (tar == NULL)

159 return ERROR;

160 if (flag == 0)

161 {

162 ClearBiTree(&(tar->lchild));

163 tar->lchild = NULL;

164 }

165 else

166 {

167 ClearBiTree(&(tar->rchild));

168 tar->rchild = NULL;

169 }

170 return OK;

171 }

172

173

174 BiTree Parent(BiTree T, Type e)//返回值为e的节点的父母

175 {

176 BiTree cur;

177

178 if (T == NULL)

179 return NULL;

180 else

181 {

182 if ((T->lchild)->data == e || (T->rchild)->data == e)

183 cur = T;

184 else

185 {

186 cur = Parent(T->lchild, e);

187 if (cur == NULL)

188 cur = Parent(T->rchild, e);

189 }

190 }

191 return cur;

192 }

193

194 BiTree LeftChild(BiTree T, Type e)//返回左孩子

195 {

196 BiTree result;

197

198 if (T == NULL)

199 return NULL;

200 else

201 {

202 if (T->data == e)

203 return T->lchild;

204 else

205 {

206 result = LeftChild(T->lchild, e);

207 if (result == NULL)

208 result = LeftChild(T->rchild, e);

209 }

210 }

211 return result;

212 }

213

214 BiTree LeftSibling(BiTree T, Type e)//返回左兄弟

215 {

216 BiTree result;

217

218 if (T->lchild == NULL || T->rchild == NULL)

219 return NULL;

220 else

221 {

222 if (T->lchild->data == e && T->rchild)

223 return T->rchild;

224 else

225 {

226 result = LeftSibling(T->lchild, e);

227 if (result == NULL)

228 result = LeftSibling(T->rchild, e);

229 }

230 }

231 return result;

232 }

233

234 int main()

235 {

236 BiTree T;

237 BitNode root;

238 BiTree temp;

239 int depth;

240

241 CreatBiTree(&T);

242 //ClearBiTree(&T);

243 //depth = BiTreeDepth(T);

244 //root = Root(T);

245 //InserInc(&T, 'd');

246 //temp = Search(T, 'a');

247 //Delete(&T, 'd');

248 //DeleteChild(&T, temp, 1);

249 //temp = Parent(T, 'c');

250 temp = LeftSibling(T, 'a');

251 return 0;

252 }