题目链接 Description Final Pan likes prime numbers very much. One day, he want to find the super prime numbers.A prime numbers $n$($n$>4) is a super prime number only if $n$-4 and $n$+4 are both prime numbers,too. Your task is really easy:Give $N$,find t…

有些问题,不做实践与猜测,可能一辈子也想不出答案,例如这题. #include<stdio.h> #include<math.h> long long x; int main() { while(~scanf("%lld",&x)){ ) printf("-1\n"); else printf("7\n"); } ; }…

Final Pan's prime numbers Time Limit: 1000MS   Memory Limit: 65535KB   64bit IO Format: %lld & %llu Submit Status Description Final Pan likes prime numbers very much. One day, he want to find the super prime numbers.A prime numbers $n$($n$>4) is a…

//真tm是乱搞 但是(乱搞的)思想很重要 解:大概就是记忆化搜索,但是原数据范围太大,不可能记下所有的情况的答案,于是我们就在记下小范围内的答案,当dfs落入这个记忆范围后,就不进一步搜索,直接返回记下来的答案,这样就起到了优化的效果,但是并不知道这种复杂度是怎么算的.然而我们由大到小排序,使得状态总可以很快地落入记忆化的范围. dfs(n,now)代表[1..n]内不会被a[now]...a[k-1]整除的数有多少,那么答案就是dfs(n,0). 转移关系如下:dfs(n,now)=dfs(…

题目链接: ztr loves lucky numbers  Time Limit: 2000/1000 MS (Java/Others)  Memory Limit: 65536/65536 K (Java/Others) 问题描述 ztr喜欢幸运数字,他对于幸运数字有两个要求 1:十进制表示法下只包含4.7 2:十进制表示法下4和7的数量相等 比如47,474477就是 而4,744,467则不是 现在ztr想知道最小的但不小于n的幸运数字是多少 输入描述 有TT(1≤T≤10​5​​)组数…

Sieve of Eratosthenes (素数筛选算法) Given a number n, print all primes smaller than or equal to n. It is also given that n is a small number. For example, if n is 10, the output should be “2, 3, 5, 7″. If n is 20, the output should be “2, 3, 5, 7, 11, 13,…

Sum of Consecutive Prime Numbers Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 22019 Accepted: 12051 Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representations d…

Sum of Consecutive Prime Numbers Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 20050   Accepted: 10989 Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representatio…

题目链接: 传送门 Sum of Consecutive Prime Numbers Time Limit: 1000MS     Memory Limit: 65536K Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representations does a given positive intege…

Problem Description Give you a lot of positive integers, just to find out how many prime numbers there are. Input There are a lot of cases. In each case, there is an integer N representing the number of integers to find. Each integer won't exceed 32-…