Sum Sum Sum
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 1033 Accepted Submission(s): 612
Problem Description
We call a positive number X P-number if there is not a positive number that is less than X and the greatest common divisor of these two numbers is bigger than 1.
Now you are given a sequence of integers. You task is to calculate the sum of P-numbers of the sequence.
Input
There are several test cases.
In each test case:
The first line contains a integer N(1≤N≤1000). The second line contains N integers. Each integer is between 1 and 1000.
Output
For each test case, output the sum of P-numbers of the sequence.
Sample Input
3
5 6 7
1
10
Sample Output
12
0
Source
题意:一个数如果与小于等于它的非负整数的最大公约数是1,那么他就是P-number,给出一个子序列,问里面的P-number之和.
题解:注意不仅仅是素数,1也是P-number
#include<stdio.h> #include<iostream> #include<string.h> #include <stdlib.h> #include<math.h> #include<algorithm> using namespace std; typedef long long LL; const int N = 1005; int p[N]; void init(){ for(int i=2;i<=1000;i++){ if(!p[i]){ for(int j=i*i;j<=1000;j+=i){ p[j] = true; } } } } int main() { init(); int n; while(scanf("%d",&n)!=EOF){ int sum = 0; for(int i=1;i<=n;i++){ int v; scanf("%d",&v); if(!p[v]) sum+=v; } printf("%d\n",sum); } return 0; }