Sum of Numbers 2-n: Repeat and While Loops

[Matt512]

Homework Statement

1.Rewrite this algorithm using a repeat until loop and then with a while loop.[/B]
Start
sum=0
Display "Input value n"
Input n
FOR( i=1 , i <=n , i+1 )
Input a value
sum=sum+value
ENDFOR
Output sum
Stop

I have some doubts if i have done the pseudo codes correctly.
2.Design an algorithm for finding the sum of the numbers 2,4,6,8,...,n
Can someone give me a leading clue on how to do it.
3.Write an algorithm to read 100 numbers then display the largest.
I am stuck midway.

Homework Equations

FOR( starting state , stopping condition, increment)

The Attempt at a Solution

Repeat until loop [/B]
Start
Repeat
sum=0
i=1
Display "Input value n"
Input n
Display "Input a value"
Input a value
sum=sum+value
i=i+1
UNTIL n>=i
Output sum
Stop

while loop.
Start
WHILE(n <>i)
sum=0
i=1
Display "Input value n"
Input n
Display "Input a value"
Input a value
sum=sum+value
i=i+1
ENDWHILE
Output sum
Stop

3.
START
count=0
sum=0
Input number
For( c=1 , c>100 , c+1)
sum=sum+value
ENDFOR
Output sum
Stop

 

[cpscdave]

Please put code (even pseudocode) inside of code tags makes it easier to read :)

Let me ask some questions:
1 (Repeat until): How does your code know where to "jump" back up to??

1 (while): When the code gets to the ENDWHILE and returns to the While <> i what gets reexecuted?
also the <> i is "NOT EQUAL TO" using it here isn't strictly wrong. But while n > i is safer. What would happen if the code accidentally jumped over n=i? 2: There are strong similarities to previous problems. This time you know already what values your going to sum up...

3: You're missing a way for the user to input a number. Also are you summing the values? or maybe you should just track something?

 

[Matt512]

1. ( Repeat until ) Since the until condition will still be false , it will go back up and repeats itself.
1. I think it will re execute the sum =0 , i = 1 , so i should put those two at the top and the while <>i after