题目:
题解:
void dfs(struct TreeNode* root, int* pre, int* ans) {
if (root == NULL) {
return;
}
dfs(root->left, pre, ans);
if (*pre == -1) {
*pre = root->val;
} else {
*ans = fmin(*ans, root->val - (*pre));
*pre = root->val;
}
dfs(root->right, pre, ans);
}
int getMinimumDifference(struct TreeNode* root) {
int ans = INT_MAX, pre = -1;
dfs(root, &pre, &ans);
return ans;
}