传送门 题意: 思路:直接上杜教筛. 知道怎么推导就很简单了,注意预处理的范围. 然后我因为预处理范围不对被zxyoi教育了(ldx你这个傻×两倍常数活该被卡TLE) 喜闻乐见 代码: #include<bits/stdc++.h> #define ri register int using namespace std; const int N=7500005,lim=7500000; typedef long long ll; namespace Sieve{ int pri[N],tot=…
Safecracker Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 10165 Accepted Submission(s): 5213 Problem Description === Op tech briefing, 2002/11/02 06:42 CST === "The item is locked in a Klein saf…