Minimize the absolute difference of sum of two subsets | function to print difference ; summation of n elements ; if divisible by 4 ; if remainder 1 or 2. In case of remainder 2 , we divide elements from 3 to n in groups of size 4 and put 1 in one group and 2 in group . This also makes difference 1. ; We put elements from 4 to n in groups of size 4. Remaining elements 1 , 2 and 3 can be divided as ( 1 , 2 ) and ( 3 ) . ; Driver code
< ? php function subsetDifference ( $ n ) { $ s = $ n * ( $ n + 1 ) / 2 ; if ( $ n % 4 == 0 ) { echo " First ▁ subset ▁ sum ▁ = ▁ " , floor ( $ s / 2 ) ; echo " Second subset sum = " , floor ( $ s / 2 ) ; echo " Difference = " } else { if ( $ n % 4 == 1 $ n % 4 == 2 ) { echo " First ▁ subset ▁ sum ▁ = ▁ " , floor ( $ s / 2 ) ; echo " Second subset sum = " , floor ( $ s / 2 + 1 ) ; echo " Difference = " } else { echo " First ▁ subset ▁ sum ▁ = ▁ " , floor ( $ s / 2 ) ; echo " Second subset sum = " , floor ( $ s / 2 ) ; echo " Difference = " ▁ , ▁ 0 ; } } } $ n = 6 ; subsetDifference ( $ n ) ; ? >