Find maximum sum taking every Kth element in the array | Function to return the maximum sum for every possible sequence such that a [ i ] + a [ i + k ] + a [ i + 2 k ] + ... + a [ i + qk ] is maximized ; Initialize the maximum with the smallest value ; Initialize the sum array with zero ; Iterate from the right ; Update the sum starting at the current element ; Update the maximum so far ; Driver code
< ? php function maxSum ( $ arr , $ n , $ K ) { $ maximum = PHP_INT_MIN ; $ sum = array ( $ n ) ; for ( $ i = $ n - 1 ; $ i >= 0 ; $ i -- ) { if ( $ i + $ K < $ n ) $ sum [ $ i ] = $ sum [ $ i + $ K ] + $ arr [ $ i ] ; else $ sum [ $ i ] = $ arr [ $ i ] ; $ maximum = max ( $ maximum , $ sum [ $ i ] ) ; } return $ maximum ; } { $ arr = array ( 3 , 6 , 4 , 7 , 2 ) ; $ n = sizeof ( $ arr ) ; $ K = 2 ; echo ( maxSum ( $ arr , $ n , $ K ) ) ; }