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
#include <bits/stdc++.h> NEW_LINE using namespace std ; int findMaximum ( int arr [ ] , int low , int 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 ] ; int 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 ) ; else return findMaximum ( arr , mid + 1 , high ) ; } int main ( ) { int arr [ ] = { 1 , 3 , 50 , 10 , 9 , 7 , 6 } ; int n = sizeof ( arr ) / sizeof ( arr [ 0 ] ) ; cout << " The ▁ maximum ▁ element ▁ is ▁ " << findMaximum ( arr , 0 , n - 1 ) ; return 0 ; }