摘要： Problem DescriptionRay又对数字的列产生了兴趣：现有四张卡片，用这四张卡片能排列出很多不同的4位数，要求按从小到大的顺序输出这些4位数。Input每组数据占一行，代表四张卡片上的数字（0<=数字<=9），如果四张卡片都是0，则输入结束。Output对每组卡片按从小到大的顺序输出所有能由这四张卡片组成的4位数，千位数字相同的在同一行，同一行中每个四位数间用空格分隔。每组输出数据间空一行，最后一组数据后面没有空行。Sample Input1 2 3 41 1 2 30 1 2 30 0 0 0Sample Output1234 1243 1324 1342 1423 阅读全文

摘要： Problem DescriptionAre you excited when you see the title "AC" ? If the answer is YES , AC it ;You must learn these two combination formulas in the school . If you have forgotten it , see the picture.Now I will give you n and m , and your task is to calculate the answer .InputIn the first 阅读全文

摘要： The number of divisors(约数) about Humble NumbersTime Limit: 2000/1000 MS (Java/Others)Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1947Accepted Submission(s): 959Problem DescriptionA number whose only prime factors are 2,3,5 or 7 is called a humble number. The sequence 1, 2, 3, 4, 5, 阅读全文

摘要： Problem DescriptionPeople in Silverland use square coins. Not only they have square shapes but also their values are square numbers. Coins with values of all square numbers up to 289 (=17^2), i.e., 1-credit coins, 4-credit coins, 9-credit coins, ..., and 289-credit coins, are available in Silverland 阅读全文