Printing first all 0 ' s ▁ x - times ▁ ▁ and ▁ decrement ▁ count ▁ of ▁ 0' s x - times and do the similar task with '1'
while ( $ count_0 > 0 $ count_1 > 0 ) { for ( $ j = 0 ; $ j < $ x && $ count_0 > 0 ; $ j ++ ) { if ( $ count_0 > 0 ) { echo "0" ; $ count_0 -- ; } } for ( $ j = 0 ; $ j < $ y && $ count_1 > 0 ; $ j ++ ) { if ( $ count_1 > 0 ) { echo "1" ; $ count_1 -- ; } } } }