Discrete Binary Search in Topcoder Tutorial -



Discrete Binary Search in Topcoder Tutorial -

i went through code given in topcoder binary search tutorial.

binary_search(lo, hi, p): while lo < hi: mid = lo + (hi-lo)/2 if p(mid) == true: hi = mid else: lo = mid+1 if p(lo) == false: complain // p(x) false x in s! homecoming lo // lo to the lowest degree x p(x) true

i not able reason why low going point want i.e. lo to the lowest degree x p(x) true ?

i have tried on examples , comes out true not able think logically.

some sort of proof using invariant maintained in loop helpful .

thanks.

my understanding more of logical one:

if while loop has terminate lo should become equal or greater hi. assuming work integers, lo equal hi , hi mid.

binary-search

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