Count number of subsets having a particular XOR value | Returns count of subsets of arr [ ] with XOR value equals to k . ; Find maximum element in arr [ ] ; Maximum possible XOR value ; Initializing all the values of dp [ i ] [ j ] as 0 ; The xor of empty subset is 0 ; Fill the dp table ; The answer is the number of subset from set arr [ 0. . n - 1 ] having XOR of elements as k ; Driver Code
< ? php function subsetXOR ( $ arr , $ n , $ k ) { $ max_ele = $ arr [ 0 ] ; for ( $ i = 1 ; $ i < $ n ; $ i ++ ) if ( $ arr [ $ i ] > $ max_ele ) $ max_ele = $ arr [ $ i ] ; $ m = ( 1 << ( int ) ( log ( $ max_ele , 2 ) + 1 ) ) - 1 ; if ( $ k > $ m ) { return 0 ; } for ( $ i = 0 ; $ i <= $ n ; $ i ++ ) for ( $ j = 0 ; $ j <= $ m ; $ j ++ ) $ dp [ $ i ] [ $ j ] = 0 ; $ dp [ 0 ] [ 0 ] = 1 ; for ( $ i = 1 ; $ i <= $ n ; $ i ++ ) for ( $ j = 0 ; $ j <= $ m ; $ j ++ ) $ dp [ $ i ] [ $ j ] = $ dp [ $ i - 1 ] [ $ j ] + $ dp [ $ i - 1 ] [ $ j ^ $ arr [ $ i - 1 ] ] ; return $ dp [ $ n ] [ $ k ] ; } $ arr = array ( 1 , 2 , 3 , 4 , 5 ) ; $ k = 4 ; $ n = sizeof ( $ arr ) ; echo " Count ▁ of ▁ subsets ▁ is ▁ " , subsetXOR ( $ arr , $ n , $ k ) ; ? >