面试

二叉树构建与遍历

最新推荐文章于 2025-12-03 14:43:29 发布

原创最新推荐文章于 2025-12-03 14:43:29 发布 · 498 阅读

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文章标签：

#面试 #null #vector #class #delete #struct

1.2008.02.28 方正国际 C++

struct Node
{
int value;
Node* pLeft;
Node* pRight;
};

void AppendValue(Node* pRoot, int value)
{
if ( pRoot )
{
  if ( pRoot->value > value )
  {
   if ( pRoot->pLeft )
   {
    AppendValue(pRoot->pLeft, value);
   }
   else
   {
    Node* node = new Node();
    node->value = value;
    node->pLeft =
    node->pRight = NULL;
    pRoot->pLeft = node;
   }

  }else
  {
   if ( pRoot->pRight )
   {
    AppendValue(pRoot->pRight, value);
   }
   else
   {
    Node* node    = new Node();
    node->value   = value;
    node->pLeft   =
    node->pRight = NULL;
    pRoot->pRight = node;
   }
  }
}
}

void MidTree(Node* pRoot)
{
if ( pRoot )
{
  MidTree(pRoot->pLeft);
  std::cout << pRoot->value << " ";
  MidTree(pRoot->pRight);
}
}

/**
* 创建排序2叉树
*/
Node* CreateSortBinaryTree(int* values, int count)
{
assert(count > 0);

Node* pRoot = new Node();
pRoot->pLeft =
pRoot->pRight = NULL;
pRoot->value = values[0];

for ( int index = 1; index < count; index++ )
{
AppendValue(pRoot, values[index]);
}

return pRoot;

}

int ChCmp(char lCh, char rCh)
{
if ( lCh >= 'A' && lCh <= 'Z' )
{
lCh = lCh - 'A' + 'a';
}

if ( rCh >= 'A' && rCh <= 'Z' )
{
rCh = rCh - 'A' + 'a';
}

if ( lCh > rCh )
{
return 1;
}
else if ( lCh < rCh )
{
return -1;
}

return 0;

}

/**
* 比较字符串，忽略大小写
*/
int StrCmp(const char* lStr, const char* rStr)
{
int res = 0;
while ( *lStr != '/0' && *rStr != '/0')
{
res = ChCmp(*lStr, *rStr);

lStr++;
rStr++;

  if ( res == 1 || res == -1 )
  {
   break;
  }

}

if ( res == 0 )
{
  if ( *lStr != '/0' )
  {
   assert(rStr == '/0');
   res = 1;
  }
  if ( *rStr != '/0' )
  {
   assert(rStr =='/0');
   res = -1;
  }
}

return res;

}

/**
* 实现类似vector的类
*/
const int INIT_ALLOC = 3;
template < class Type >
class MyVector
{
public:

MyVector()
{
  m_values = (Type*)::malloc(INIT_ALLOC*sizeof(Type));
  m_size    = 0;
  m_caplity = INIT_ALLOC;
}

~MyVector()
{
free(m_values);
  m_values = NULL;
  m_size    =
  m_caplity = 0;
}

void Append(const Type& value)
{
  m_size += 1;
  Alloc();
  m_values[m_size - 1] = value;
}

bool Delete(int index)
{
  if ( index < m_size && index >=0 )
  {
   if ( m_size > (index + 1) )
       ::memcpy(m_values+index, m_values+index+1, (m_size - index - 1)*sizeof(Type));
   m_size--;
   return true;
  }
  return false;
}

void Print()
{
  std::cout << std::endl;
  for ( int i = 0; i < m_size; i++ )
  {
   std::cout << m_values[i] << " ";
  }
  std::cout << std::endl;
}

private:
void Alloc()
{
  if ( m_caplity < m_size )
  {
   m_caplity += INIT_ALLOC;
   if ( m_values )
       m_values = (Type*)::realloc(m_values, m_caplity * sizeof(Type));
   else
    m_values = (Type*)::malloc(m_caplity * sizeof(Type));
  }
}
int   m_caplity;
int   m_size;
Type* m_values;
};