leaf
if ( ss == se ) { st [ i ] = ss ; return ; } int mid = ( ss + se ) / 2 ; SegmentTreeConstruction ( ss , mid , left ( i ) ) ; SegmentTreeConstruction ( mid + 1 , se , right ( i ) ) ; if ( l . get ( st [ left ( i ) ] ) < l . get ( st [ right ( i ) ] ) ) st [ i ] = st [ left ( i ) ] ; else st [ i ] = st [ right ( i ) ] ; }