摘要:
hdu 1099 Lottery题意:1~n编号的彩票,要买全,等概率条件下平均要买几张。已经买了m张时,买中剩下的概率为1-m/n,则要买的张数为1/(1-m/n)n=2,s=1+1/(1-1/2);n=3,s=1+1/(1-1/3)+1/(1-2/3)s=1+1/(1-1/n)+1/(1-2/n 阅读全文
摘要:
Ignatius's puzzle Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 9859 Accepted Submission(s): 68 阅读全文