Algorithms, flow charts and bin packingEdexcel International A Level Maths: Mind map

Exam questions on Algorithms, flow charts and bin packing

1. An algorithm is described as follows. Step 1: Input a number $N$. Step 2: Set $S$ equal to 0. Step 3: Add $N$ to $S$. Step 4: Replace $N$ by $N-3$. Step 5: If $N>0$, go to Step 3. Step 6: Print $S$.
   Find the value printed when the input is $N=20$.2 marks
2. Eight files of sizes 9, 7, 11, 6, 5, 13, 12 and 10 megabytes (MB) are to be stored on memory sticks. Each memory stick can hold at most 20 MB.
   Use the first-fit decreasing algorithm to pack the files, and write down the contents of each memory stick.2 marks
3. An algorithm is described as follows. Step 1: Input two positive integers $A$ and $B$, with $A>B$. Step 2: Let $R$ be the remainder when $A$ is divided by $B$. Step 3: If $R=0$, print $B$ and stop. Step 4: Replace $A$ by $B$ and $B$ by $R$, then go to Step 2.
   Apply the algorithm to the inputs $A=252$ and $B=105$, showing the values of $A$, $B$ and $R$ each time Step 2 is performed.3 marks