solve.cpp

#include <cstdlib>
using namespace std;
struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};
static inline int abs(int a, int b)
{
	return a > b ? a - b : b - a;
}
class Solution {
public:
    bool isBalanced(TreeNode *root) {
	    bool unbalenced = false;
	    getHeight(unbalenced, root);
	    return !unbalenced;
    }
    int getHeight(bool &unbalenced, TreeNode *root) {
	    if (root == NULL || unbalenced)
		    return -1;
	    int left = getHeight(unbalenced, root->left);
	    int right = getHeight(unbalenced, root->right);
	    if (abs(left, right) > 1) {
		    unbalenced = true;
	    }
	    return 1 + (left > right ? left : right);
    }

};
int main(int argc, char **argv)
{
	return 0;
}