arrays - What is this trying to tell me? -


i reading book "how solve computer" rg dromey. stuck on sentence trying explain termination of loops. here goes problem:

suppose wish establish array of n elements in strictly ascending order (i.e. a[1] < a[2] < ... < a[n]) . can use following instructions:

a[n+1] := a[n]; := 1; while a[i] < a[i+1] := i+1

(now if n number of elements, i stand in case? stand values?)

if n assigned value 5 , data set 2, 3, 5, 11, 14, first assignment prior loop result in array configuration below:

(this confused.)

a[1]  a[2]  a[3]  a[4]  a[5]  a[6] 2     3     5     11    14    14

the 2 14's guarantee test a[i] < a[i+1] false when i = n , loop terminate correctly when i = n if not before.

(this confusing.)

i index
:= 1; means equal 1
:= i+1 means add 1

n = 5

a[5] = 14
a[5+1] = a[6] = 14

14 < 14 false - loop terminates


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