hpuspring的博客

点击打开链接Problem DescriptionGiven a number N, you are asked to count the number of integers between A and B inclusive which are relatively prime to N.Two integers are said to be co-

void pr(int k) //求k的质因子 { num = 0; for (int i = 2 ; i * i <= k ; i++) { if (k % i == 0) { p[num++] = i; while (k % i == 0)