Largest subarray with equal number of 0 s and 1 s | This function Prints the starting and ending indexes of the largest subarray with equal number of 0 s and 1 s . Also returns the size of such subarray . ; Pick a starting point as i ; Consider all subarrays starting from i ; If this is a 0 sum subarray , then compare it with maximum size subarray calculated so far ; Driver Code
< ? php function findSubArray ( & $ arr , $ n ) { $ sum = 0 ; $ maxsize = -1 ; for ( $ i = 0 ; $ i < $ n - 1 ; $ i ++ ) { $ sum = ( $ arr [ $ i ] == 0 ) ? -1 : 1 ; for ( $ j = $ i + 1 ; $ j < $ n ; $ j ++ ) { ( $ arr [ $ j ] == 0 ) ? ( $ sum += -1 ) : ( $ sum += 1 ) ; if ( $ sum == 0 && $ maxsize < $ j - $ i + 1 ) { $ maxsize = $ j - $ i + 1 ; $ startindex = $ i ; } } } if ( $ maxsize == -1 ) echo " No ▁ such ▁ subarray " ; else echo $ startindex . " ▁ to ▁ " . ( $ startindex + $ maxsize - 1 ) ; return $ maxsize ; } $ arr = array ( 1 , 0 , 0 , 1 , 0 , 1 , 1 ) ; $ size = sizeof ( $ arr ) ; findSubArray ( $ arr , $ size ) ; ? >