Update 100+ Python challenging programming exercises.txt

Added a question and solution for a program called lastoccurrence(). Bit more difficult for beginners, however, it is doable. This should not be much of a challenge for experienced programmers.

Author: Rohit-beep-droid

100+ Python challenging programming exercises.txt

@@ -2371,5 +2371,35 @@ solutions=solve(numheads,numlegs)
 print solutions
 
 #----------------------------------------#
+Level 2:
+Slightly difficult for beginners but doable,
+however, should be relatively easy for 
+experienced programmers.
 
+Question:
+Write a program that iterates through a 2D matrix
+and return the last occurrence location of a integer.
+
+Example 1:
+[[3,2,3],[0,5,3],[9,1,7]] --> Return the last occurrence of the integer 3.
+The program should return (1,2).
+
+Example 2:
+[[3,2,3],[0,5,3],[9,1,7]] --> Return the last occurrence of the integer 1.
+The program should return (2,1).
+
+Example 3:
+[[3,2,3],[0,5,3],[9,1,7],[2,0,2]] --> Return the last occurrence of the integer 2.
+The program should return (3,2).
 
+Hints:
+Use range(), len(), and mutiple loops to traverse
+the mutiple lists within the list.
+
+Solution:
+def lastoccurrence(numlist, num):
+    for i in range(len(numlist)-1,-1,-1):
+        for j in range(len(numlist[i])-1,-1,-1):
+	    if numlist[i][j] == num:
+	        return i,j
+#----------------------------------------#