added LGIS solution

LGIS.py

@@ -0,0 +1,70 @@
+#!/usr/bin/python
+
+# Solution to the LGIS Rosalind Problem - Longest Increasing Subsequence
+# Author: Peter Vlasveld
+# Date: 18/01/2019
+import copy
+
+#get input
+f1 = open("rosalind_lgis.txt")
+content = f1.readlines()
+f1.close()
+
+#get array out of content
+arr = content[1].split( )
+
+#function to find longest increasing subsequence of arr
+def inc (arr):
+    #set s array to a list of a list of the first value in arr
+    s = [[arr[0]]]
+    #loop through arr skipping the first value
+    for i in xrange(1,len(arr)):
+        #if this arr value is greater than the last element in the last list of s, 
+        # then duplicate the last list and append the new value
+        if int(arr[i]) > int(s[len(s)-1][len(s[len(s)-1])-1]):
+            tempLis = copy.deepcopy(s[len(s)-1])
+            tempLis.append(arr[i])
+            s.append(tempLis)
+        #else if the first list of s is greater than the arr value, make the arr value the new first list
+        elif int(s[0][0]) > int(arr[i]):
+            s[0] = copy.deepcopy([arr[i]])
+        #otherwise, find the list in s where the last value is less greater than the arr value,
+        # and replace it with the list before it, with the new value appended to the end
+        else:
+            for j in xrange(0, len(s)):
+                if int(arr[i]) < int(s[j][len(s[j])-1]):
+                    s[j] = copy.deepcopy(s[j-1])
+                    s[j].append(arr[i])
+                    break
+    #return the last element of s which at this point is the longest increasing subsequence
+    return s[len(s)-1]
+
+#find the longest decreasing subsequence
+#the logic is the exact same as the above increasing function, 
+# just with all of the greater-than and less-than operators turned around
+def dec (arr):
+    s = [[arr[0]]]
+    for i in xrange(1,len(arr)):
+        if int(arr[i]) < int(s[len(s)-1][len(s[len(s)-1])-1]):
+            tempLis = copy.deepcopy(s[len(s)-1])
+            tempLis.append(arr[i])
+            s.append(tempLis)
+        elif int(s[0][0]) < int(arr[i]):
+            s[0] = copy.deepcopy([arr[i]])
+        else:
+            for j in xrange(0, len(s)):
+                if int(arr[i]) > int(s[j][len(s[j])-1]):
+                    s[j] = copy.deepcopy(s[j-1])
+                    s[j].append(arr[i])
+                    break
+    return s[len(s)-1]
+
+#run the functions
+inc = inc(arr)
+dec = dec(arr)
+
+#print the output to a file
+f2 = open("output.txt", "w")
+f2.write(" ".join(inc) + "\n")
+f2.write(" ".join(dec))
+f2.close()