construct-binary-tree-from-inord

class Solution {
public:
    TreeNode *buildTree(vector<int> &inorder, vector<int> &postorder) {
        return create(inorder,postorder,0,inorder.size()-1,0,postorder.size()-1);
    }
    TreeNode *create(vector<int>in,vector<int>post,int inL,int inR,int postL,int postR)
    {
        if(postL>postR)return NULL;
        TreeNode*root=new TreeNode(post[postR]);
        int k;
        for(k=inL;k<=inR;k++)
        {
            if(in[k]==root->val)break;
        }
        int numleft=k-inL;
        root->left=create(in,post,inL,k-1,postL,postL+numleft-1);
        root->right=create(in,post,k+1,inR,postL+numleft,postR-1);
        return root;
    }
};