fix Makefile for compatibility of cxx11
fix Makefile for compatibility of cxx11

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