The　algorithm　presented　solves　the　problem　within　minimal　levels　amount　of　search　that　when　practical　applications　can　present　required　real　bound　on　the　worst　case,　and　how　to　attain　this　demand　within　minimal　amount　of　search.　Sandholm　have　proved　that　in　order　to　establish　any　worst　case　bound　K(n),　it　is　necessary　to　search　the　lowest　two　levels　of　the　coalition　structure　graph,　and　the　bound　is　n　(the　number　of　agents).　Based　on　this,　using　our　algorithm,　after　the　search　of　the　lowest　two　levels,　the　bound　K(n)≤3　can　be　attained　with　the　searching　of　only　one　level,　and　the　bound　K(n)≤2　can　be　attained　with　the　searching　of　two　levels　at　most.　Using　our　algorithm,　the　amount　of　search　needed　to　attain　the　bound　is　drastically　cut　down　compared　with　the　algorithm　proposed　by　Sandholm　et　al.