sunshine_lyn的博客

With the 2010 FIFA World Cup running, football fans the world over were becoming increasingly excited as the best players from the best teams doing battles for the World Cup trophy in South Africa. Si...

A reversible prime in any number system is a prime whose "reverse" in that number system is also a prime. For example in the decimal system 73 is a reversible prime because its reverse 37 is also a pr...

让我们定义 dn 为：dn = pn+1 - pn，其中 pi 是第i个素数。显然有 d1=1 且对于n>1有 dn 是偶数。“素数对猜想”认为“存在无穷多对相邻且差为2的素数”。现给定任意正整数N (< 105)，请计算不超过N的满足猜想的素数对的个数。输入格式：每个测试输入包含1个测试用例，给出正整数N。输出格式：每个测试用例的输出占一行，不超过N的满足猜想的素数对的个数。输入样例...

People in Mars represent the colors in their computers in a similar way as the Earth people. That is, a color is represented by a 6-digit number, where the first 2 digits are for Red, the middle 2 dig...