POJ 3518 Prime Gap(素数) id=3518">http://poj.org/problem? id=3518 题意: 给你一个数.假设该数是素数就输出0. 否则输出比这个数大的素数与比这个数小的素数的差值. 分析: 明显本题先要用筛选法求出130W(个素数)以内的全部素数. 然后推断给的数是否是素数就可以. 假设不是素数.那么就找出它在素数素组内的上界和下界,输出两个素数的差值就可以. 筛选法求素数可见: http://blog.csdn.net/u013480600/a…

Prime Gap 这里直接写中文了 Descriptions: 对于一个数n,若n为素数则输出0,否则找到距离n最小的两个素数,一个大于n,一个小于n,输出他们的差(正数) Input 多组输入 每行包含一个数n 若n为0,程序结束 Output 对于每个测试数据,输出一个答案占一行 Sample Input 10 11 27 2 492170 0 Sample Output 4 0 6 0 114 题目链接: https://vjudge.net/problem/UVA-1644 水题,先求…

[题意简述]:输入一个数,假设这个数是素数就输出0,假设不是素数就输出离它近期的两个素数的差值,叫做Prime Gap. [分析]:这题过得非常险.由于我是打的素数表. 由于最大的素数是1299709,所以注意在打表时要使用long long.否则程序应该不能执行.注意这一点应该就能够了. 积累! // 2984K 235Ms #include<iostream> using namespace std; #define N 2000001 bool isprime[N]; long long…

Prime Gap Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 7392   Accepted: 4291 Description The sequence of n − 1 consecutive composite numbers (positive integers that are not prime and not equal to 1) lying between two successive prime…

题意:给定一个数 n,求它后一个素数和前一个素数差. 析:先打表,再二分查找. 代码如下: #pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib> #include <cmath> #include <iostream> #include <cstring&…

POJ 1488 题目大意:给定一篇文章,将它的左引号转成 ``(1的左边),右引号转成 ''(两个 ' ) 解题思路:水题,设置一个bool变量标记是左引号还是右引号即可 /* POJ 1488 Tex Quotes --- 水题 */ #include <cstdio> #include <cstring> int main() { #ifdef _LOCAL freopen("D:\\input.txt", "r", stdin); #…

http://poj.org/problem?id=3461 直接KMP就好.水题 #include<cstdio> #include<cstring> const int MAXN=10000+10; const int MAXM=1000000+10; char P[MAXN],T[MAXM]; int f[MAXN],n,m,ans; void getFail() { f[0]=f[1]=0; for(int i=1;i<n;i++){ int j = f[i]; wh…

Biorhythms Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 110991   Accepted: 34541 Description Some people believe that there are three cycles in a person's life that start the day he or she is born. These three cycles are the physical,…

487-3279 Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 236746   Accepted: 41288 Description Businesses like to have memorable telephone numbers. One way to make a telephone number memorable is to have it spell a memorable word or phras…

Hangover Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 99450   Accepted: 48213 Description How far can you make a stack of cards overhang a table? If you have one card, you can create a maximum overhang of half a card length. (We're as…