【莫比乌斯反演-求序列中数字两两互质的对数】ACdreamoj Number theory 1114
NumbertheoryTimeLimit:2000/1000MS(Java/Others)MemoryLimit:128000/64000KB(Java/Others)ProblemDescriptionThistimeIwillgiveyousomestraight!Giveyouasequencea1,a2,a3...,an,thequestionishowmanypair(ai,aj)th