Re: searching for missing element in an array

On Thu, 29 May 2008 12:39:08 +0100, rossum wrote:

On Thu, 29 May 2008 03:10:32 -0700 (PDT), srk <kumarsr@xxxxxxxxx> wrote:

Hi,
Suppose we have n numbers(from 1 to n) and there is an array of size
n-1. How can we find, which number is missing from the array if numbers
1 to n are being placed in array randomly.

Thanks
SRK
Total all the numbers in the array.

The numbers from 1 to n add up to (n * (n + 1)) / 2.

The difference is the missing number.

rossum

An other option would be to *multiply* all the entries, and divide n! by
the sum ;-)

AvK
.

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