Added 4, bare with me, i am sleepy

1_Data_Storage.md

@@ -33,7 +33,7 @@ B49F
 011000 - D
 101101 - F
 
-### What is the smallest negative integer that can be represented in a two's complement system in which each value is represented by eight bits?
+  # What is the smallest negative integer that can be represented in a two's complement system in which each value is represented by eight bits?
 10000000, -128 (either is correct)
 
 ### Which of the following data storage systems provides the most efficient random access to individual data items?

4_Algorithms.md

@@ -0,0 +1,81 @@
+### In general, an algorithm in which of the following categories is considered more efficient?
+Θ(log n)
+
+### Suppose the statement "X is an integer and X < 5" is a loop invariant at the point at which the test for termination is performed in the loop outlined below.
+```
+repeat ( . . . )
+until (X > 3)
+```
+### At the end of this loop, X equals?
+4
+
+### What sequence of numbers would be printed if the following procedure were executed with the value of N being 0?
+```
+procedure xxx (N)
+
+   print the value of N;
+
+   if (N < 2) then
+
+      (apply the procedure xxx to the value N + 1)
+
+   else
+
+      (print the value of N)
+
+print the value of N
+```
+0,1,2,2,2,1,0
+
+### What sequence of numbers would be printed if the procedure named xxx as described below were executed with the value of N being 2?
+
+```
+procedure xxx(N)
+  print the value of N;
+  if (N<3)
+    then (apply procedure yyy to the value 4)
+procedure yyy(N)
+  print the value of N;
+  apply the procedure xxx to the value 5
+  print the value of N
+```
+2,4,5,5,4,2
+
+### Which of the following is not a way of representing algorithms?
+Stepwise refinement
+
+### Q6 is a table again
+![Table](https://media.discordapp.net/attachments/458628210272239626/1038241407078506536/image.png?width=638&height=335)
+
+### Preconditions, postconditions, and loop invariants are examples of which of the following?
+Assertions
+
+### The binary search algorithm is an example of an algorithm in which of the following classes?
+Θ(log n)
+
+### Under the assumption that N takes on only integer values, which of the following is the termination condition in the following recursive procedure?
+
+```
+procedure xxx (N)
+
+   if (N < 5) then
+
+      (apply the procedure xxx to the value N + 1)
+
+    else
+
+      (print the value of N)
+```
+N > 4
+
+### When searching within the list ` Lewis, Maurice, Nathan, Oliver, Pat, Quincy, Roger, Stan, Tom` which of the following entries will be found most quickly using the binary search algorithm?
+Pat
+
+### Which of the following set of instructions defines an algorithm in the formal, strict sense?
+```
+X ← 3;
+
+while (X < 5)do
+
+  (X ← X + 1)
+```