## September 23, 2014

### 100 people standing in a circle in an order 1 to 100

100 people standing in a circle in an order 1 to 100. No.1 has a sword. He kills next person (i.e.no. 2 )and gives sword to next to next (i.e no.3). All person does the same until only 1 survives. Which number survives at the last?

Rajesh said...

73

Anonymous said...

No.73 will survive

annapoorna said...

99

reybo1 said...

reybo1 says 97

Shivraj said...

73
is there an intelligent way of finding solution.I created a binary tree,with each branch having common scheme for elements.

57

Anonymous said...

Looks like 73 to me. I just created the numbers 1-100 and started crossing them off.

Aaron Shulkin said...

Person number 1

Anonymous said...

#1

Anonymous said...

the first person #1 because no one killed #1

Anonymous said...

# 1 was the person who sarted the patteren

dogtag114 said...

First... mass genecide of even numbers (no offense to our even numbered friends).

Last death is 93 at the hands of 61.

No elegant solution other than excel model...

MK Abdurahiman said...

73

Anonymous said...

73.
start at 1 +2
next set +4
next set +8
next set +16
next set +32.
9+32+32=73 End.

Nathan Johnson said...

73. Just make a list of numbers and cross off every other number till only one is left. 73 is the last man standing.

Anonymous said...

In the first round 99 kills 100 and gives sword to person no1 and then in second round 97 kills 99 and gives sword to 1 ...so like this..doesn't 1 keeps alive everytime? How do we cancel the nos such that 1 gets killed??

Thomas Riley said...

1. All evens die.
2. 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, ... , 93, 97 live (97 kills 99)
3. 1, 9, 17, 25, 33, 41, 49, 57, 65, 73, 81, 89, 97 live (97 kills 1)
4. 9, 25, 41, 57, 73, 89 live (89 kills 97)
5. 9, 41, 73 live (73 kills 89)
6. 9, 73 live (73 kills 9)
7. 73 is still alive. However, 73 is the next number, and thus 73 kills 73. The sword disintegrates into the null and infinite.

Literature Lover said...

You can only kill person next to you... so 73 is the lucky one to be alive with Excalibur! Now try with 1 kills not 2 but 3 and gives it to 4 and so on.... have fun!

sql2008 said...

The solution is number 73

I find the solution by building a Javascript algorithm that can be found at People with Sword Around a Circle

Hope it helps