Given an array arr [ ] , find the maximum j | For a given array [ ] arr , calculates the maximum j a i such that arr [ j ] > arr [ i ] ; Create an array maxfromEnd ; We store this as current answer and look for further larger number to the right side ; Keeping a track of the maximum difference in indices
let v = [ 34 , 8 , 10 , 3 , 2 , 80 , 30 , 33 , 1 ] ; let n = v . length ; let maxFromEnd = new Array ( n + 1 ) ; for ( let i = 0 ; i < maxFromEnd . length ; i ++ ) maxFromEnd [ i ] = Number . MIN_VALUE ; for ( let i = v . length - 1 ; i >= 0 ; i -- ) { maxFromEnd [ i ] = Math . max ( maxFromEnd [ i + 1 ] , v [ i ] ) ; } let result = 0 ; for ( let i = 0 ; i < v . length ; i ++ ) { let low = i + 1 , high = v . length - 1 , ans = i ; while ( low <= high ) { let mid = parseInt ( ( low + high ) / 2 , 10 ) ; if ( v [ i ] <= maxFromEnd [ mid ] ) { ans = Math . max ( ans , mid ) ; low = mid + 1 ; } else { high = mid - 1 ; } } result = Math . max ( result , ans - i ) ; } document . write ( result ) ;