optimize astar alg, added verbose comments
optimize astar alg, added verbose comments

NoSmartNoMan/algorithms,qvex/algorithms,switchkiller/algorithms,zhenglaizhang/algorithms,fengzhyuan/algorithms,sigma-random/algorithms,shijiaxing/algorithms,noname007/algorithms,greyg00s/algorithms,dumubuchenglin/algorithms,fw1121/algorithms,hengwusanren/algorithms,xtaci/algorithms,jacklicn/algorithms,xtaci/algorithms,M4573R/algorithms-1,allengaller/algorithms,zhenglaizhang/algorithms,hengwusanren/algorithms,allengaller/algorithms,fw1121/algorithms,tempbottle/algorithms,jacklicn/algorithms,M4573R/algorithms-1,lanbing510/Algorithms,lanbing510/Algorithms,fengzhyuan/algorithms,xmfbit/algorithms,NoSmartNoMan/algorithms,switchkiller/algorithms,ashwini0529/algorithms-1,tempbottle/algorithms,dumubuchenglin/algorithms,ashwini0529/algorithms-1,greyg00s/algorithms,shijiaxing/algorithms,qvex/algorithms,xmfbit/algorithms,noname007/algorithms,sigma-random/algorithms