對稱的二叉樹與順時針打印矩陣

對稱的二叉樹

class Solution {
public:
    bool Compare(TreeNode* left,TreeNode* right){
        if(left == NULL && right == NULL)
            return true;
        if(left == NULL || right == NULL)
            return false;
        return left->val == right->val && Compare(left->left,right->right)
            && Compare(left->right,right->left);
    }
    bool isSymmetrical(TreeNode* pRoot)
    {
        if(pRoot == NULL)
            return true;
        return Compare(pRoot->left,pRoot->right);
    }

};

順時針打印矩陣

void print_circle(vector< vector<int> > &arr,int a,int b,int c,int d)
{
	if (a == c)
	{
		for(int i=b;i<=d;i++)
			cout<<arr[a][i]<<" ";
	}
	else if(b == d)
	{
		for(int i=a;i<=c;i++)
			cout<<arr[i][b]<<" ";
	}
	else
	{
		int row = a;
		int column = b;
		while(column != d)
			cout<<arr[a][column++]<<" ";
		while(row != c)
			cout<<arr[row++][column]<<" ";
		while(column != b)
			cout<<arr[c][column--]<<" ";
		while(row != a)
			cout<<arr[row--][b]<<" ";
	}
}