diff --git a/chapterSearch.tex b/chapterSearch.tex
index ca2faf2..6f156b6 100644
--- a/chapterSearch.tex
+++ b/chapterSearch.tex
@@ -129,20 +129,22 @@ \subsection{Extreme-value problems}\label{extremeValueProblem}
 def LIS(self, A):
     n = len(A)
     MIN = [-1 for _ in xrange(n+1)]
-    
-    l = 1
-    for i in xrange(1, n):
-        if A[i] > A[MIN[l]]:
-            l += 1
-            MIN[l] = i
-        else:
-            j = self.bin_search(MIN, A, A[i], 1, l+1)
-            MIN[j] = i
-
-    return l
+    k = 1
+    MIN[k] = A[0]  # store value
+    for v in A[1:]:
+        idx = bisect.bisect_left(MIN, v, 1, k+1)
+        MIN[idx] = v
+        k += 1 if idx == k+1 else 0
+
+    return k
 \end{python}
 If need to return the LIS itself. 
 \begin{python}
+    n = len(A)
+    MIN = [-1 for _ in xrange(n+1)]
+    RET = [-1 for _ in xrange(n)]
+    l = 1
+    MIN[l] = 0  # store index
     for i in xrange(1, n):
         if A[i] > A[MIN[l]]:
             l += 1
diff --git a/chapterTree.tex b/chapterTree.tex
index 7c88c4c..1bca6a9 100644
--- a/chapterTree.tex
+++ b/chapterTree.tex
@@ -136,7 +136,7 @@ \subsection{Basic Operations}
 
 Rightmost node can be similarly found.
 
-\runinhead{Diameter of a tree.} The diameter of a tree $\equiv$ longest path in the tree.
+\runinhead{Diameter of a tree (graph).} The diameter of a tree $\equiv$ longest path in the tree.
 
 Core clues:
 \begin{enumerate}