Find the maximum element in an array which is first increasing and then decreasing |  ; Base Case : Only one element is present in arr [ low . . high ] ; If there are two elements and first is greater then the first element is maximum ; If there are two elements and second is greater then the second element is maximum ; If we reach a point where arr [ mid ] is greater than both of its adjacent elements arr [ mid - 1 ] and arr [ mid + 1 ] , then arr [ mid ] is the maximum element ; If arr [ mid ] is greater than the next element and smaller than the previous element then maximum lies on left side of mid ; when arr [ mid ] is greater than arr [ mid - 1 ] and smaller than arr [ mid + 1 ] ; Driver code
function findMaximum ( arr , low , high ) { if ( low == high ) return arr [ low ] ; if ( ( high == low + 1 ) && arr [ low ] >= arr [ high ] ) return arr [ low ] ; if ( ( high == low + 1 ) && arr [ low ] < arr [ high ] ) return arr [ high ] ; mid = ( low + high ) / 2 ; if ( arr [ mid ] > arr [ mid + 1 ] && arr [ mid ] > arr [ mid - 1 ] ) return arr [ mid ] ; if ( arr [ mid ] > arr [ mid + 1 ] && arr [ mid ] < arr [ mid - 1 ] ) return findMaximum ( arr , low , mid - 1 ) ; return findMaximum ( arr , mid + 1 , high ) ; } arr = new Array ( 1 , 3 , 50 , 10 , 9 , 7 , 6 ) ; n = arr . length ; document . write ( " " + " " + findMaximum ( arr , 0 , n - 1 ) ) ;