What are the key elements of an algorithm?

The following code does not represent an algorithm. Why?

int sum$($int $n)\{$

int total $=0$;

while $(n>0)($

total $=$ total $+n$;

$\}$

return total;

$\}$

Without knowing anything about the usage, if you had to choose between Insertion Sort

and Quick Sort, which would you choose and why?

What is the Big Oh efficiency class of the following well$-$known algorithm? Also, set up the

summation equation for the algorithm.

$\frac{a}{?}$

$=w1$ for ilarr$0ton-2do$

$q$ for jlarr$0ton-2do$

$ifA[j+1]$

What $is$ the Big $Oh$ efficiency class $of$ the following well$-$known algorithm? Also, set $up$ the

recursive time cost equation for this algorithm.

void tower$(inta,$ char from, char aux, char $to)\{$

$if(a=w1)\}.$

cout disc $1$ from $"$ from

$$;

return;

$\}$

elsef

tower$($a$-1,$ from, to$,$ aux$)$ ;

tower$($a$-1,$ aux, from, to$)$ ;

$\}$

$1$

What is the Big Oh efficiency class of classic recursive Fibonacci? Even though it's terrible,

why might we still use this algorithm?

What's the difference between the Decrease$-$and$-$Conquer and Divide$-$and$-$Conquer families

of algorithms?

Name one example for each of Decrease$-$and$-$Conquer and Divide$-$and$-$Conquer algorithms.

Explain why you selected each example.