Permute two arrays such that sum of every pair is greater or equal to K | Check whether any permutation exists which satisfy the condition . ; Sort the array a [ ] in decreasing order . ; Sort the array b [ ] in increasing order . ; Checking condition on each index . ; Driven Program
< ? php function isPossible ( $ a , $ b , $ n , $ k ) { sort ( $ a ) ; rsort ( $ b ) ; for ( $ i = 0 ; $ i < $ n ; $ i ++ ) if ( $ a [ $ i ] + $ b [ $ i ] < $ k ) return false ; return true ; } $ a = array ( 2 , 1 , 3 ) ; $ b = array ( 7 , 8 , 9 ) ; $ k = 10 ; $ n = count ( $ a ) ; if ( isPossible ( $ a , $ b , $ n , $ k ) ) echo " Yes " ; else echo " No " ; ? >