Count Strictly Increasing Subarrays | PHP program to count number of strictly increasing subarrays in O ( n ) time . ; Initialize result ; Initialize length of current increasing subarray ; Traverse through the array ; If arr [ i + 1 ] is greater than arr [ i ] , then increment length ; Else Update count and reset length ; If last length is more than 1 ; Driver Code
< ? php function countIncreasing ( $ arr , $ n ) { $ cnt = 0 ; $ len = 1 ; for ( $ i = 0 ; $ i < $ n - 1 ; ++ $ i ) { if ( $ arr [ $ i + 1 ] > $ arr [ $ i ] ) $ len ++ ; else { $ cnt += ( ( ( $ len - 1 ) * $ len ) / 2 ) ; $ len = 1 ; } } if ( $ len > 1 ) $ cnt += ( ( ( $ len - 1 ) * $ len ) / 2 ) ; return $ cnt ; } $ arr = array ( 1 , 2 , 2 , 4 ) ; $ n = count ( $ arr ) ; echo " Count ▁ of ▁ strictly ▁ increasing ▁ subarrays ▁ is ▁ " , countIncreasing ( $ arr , $ n ) ; ? >