判别两棵树是否相等。

int compareTree(TreeNode* tree1, TreeNode* tree2) //用分治的方法做，比较当前根，然后比较左子树和右子树 {bool tree1IsNull = (tree1==NULL); bool tree2IsNull = (tree2==NULL); if(tree1IsNull != tree2IsNull) { return 1; } if(tree1IsNull && tree2IsNull) {//如果两个都是NULL，则相等 return 0; }//如果根节点不相等，直接返回不相等，否则的话，看看他们孩子相等不相等 if(tree1->c != tree2->c) { 　return 1; } return (compareTree(tree1->left,tree2->left)&compareTree(tree1->right,tree2->right)) (compareTree(tree1->left,tree2->right)&compareTree(tree1->right,tree2->left)); }//算法结束