Given two arrays count all pairs whose sum is an odd number | Function that returns the number of pairs ; Count of odd and even numbers ; Traverse in the first array and count the number of odd and evene numbers in them ; Traverse in the second array and count the number of odd and evene numbers in them ; Count the number of pairs ; Return the number of pairs ; Driver code
< ? php function count_pairs ( $ a , $ b , $ n , $ m ) { $ odd1 = 0 ; $ even1 = 0 ; $ odd2 = 0 ; $ even2 = 0 ; for ( $ i = 0 ; $ i < $ n ; $ i ++ ) { if ( $ a [ $ i ] % 2 ) $ odd1 ++ ; else $ even1 ++ ; } for ( $ i = 0 ; $ i < $ m ; $ i ++ ) { if ( $ b [ $ i ] % 2 ) $ odd2 ++ ; else $ even2 ++ ; } $ pairs = min ( $ odd1 , $ even2 ) + min ( $ odd2 , $ even1 ) ; return $ pairs ; } $ a = array ( 9 , 14 , 6 , 2 , 11 ) ; $ b = array ( 8 , 4 , 7 , 20 ) ; $ n = count ( $ a ) ; $ m = count ( $ b ) ; echo count_pairs ( $ a , $ b , $ n , $ m ) ; ? >