试题03 数素数

题目描述：令Pi表示第i个素数。现任给两个正整数M <= N <= 10000，请输出PM到PN的所有素数。

输入描述:

输入在一行中给出M和N，其间以空格分隔。

输出描述:

输出从PM到PN的所有素数，每10个数字占1行，其间以空格分隔，但行末不得有多余空格。

输入例子:

5 27

输出例子:

11 13 17 19 23 29 31 37 41 43

47 53 59 61 67 71 73 79 83 89

97 101 103

解析：

注意事项：

• 数组注意下表与M,N的对应；
• 为图方便直接声明了大小为MAXSIZE的数组，array[M]存的PM，故而数组必须超过10000，否则输入为10000,10000时就会出现数组array[10000]数组访问越界的错误；
• 输出格式要注意：要求每十个数字要换行，且行末不可有空格。

解法实例：

1

#include<iostream>
#include<cmath>
int main()
{
  using namespace std;
  int m,n,count = 0;
  cin >> m >> n;
  for (int i = 2;count <= n;i++)
  {
    int temp = 0;
    for (int j = 2;j <= sqrt(i);j++)
      if (i % j == 0)
        ++temp;
    if (temp == 0)
      ++count;
    if (count >= m && count <= n && temp == 0)
    {
      cout << i;
      if ((count - m) % 10 == 9)
        cout << "\n";
      else if (count != n)
        cout << " ";
    }
  }
  cout << endl;
  return 0;
}

2

import java.util.Scanner;   public class Main {       public static void main(String[] args) {         // TODO Auto-generated method stub         Scanner in = new Scanner(System.in);         int begin = in.nextInt();         int end = in.nextInt();         in.close();         int[] array = new int[end];         int index = 0;         int i = 2;         while (index < end) {             if (Isprime(i)) {                 array[index] = i;                 index++;             }             i++;         }         int ten = 0;         for (int j = (begin - 1); j < end; j++) {             System.out.print(array[j]);             ten++;             if (ten % 10 == 0) {                 System.out.println();                 continue;             }             if (j != end - 1) {                 System.out.print(" ");             }         }     }               public static boolean Isprime(int n) {         if (n == 1) {             return false;         } else if (n == 2) {             return true;         } else if (n % 2 == 0) {             return false;         } else {                           for (int i = 3; i <= (int)Math.sqrt(n); i += 2) {                 if (n % i == 0) {                     return false;                 }             }             return true;         }       } }

3

#include<stdio.h> #include<math.h> int is_prime(int num) {   int i;   if(num==2)     return 1;   else   {     for(i=2;i<=sqrt(num);i++)     {       if(num%i==0)         return 0;     }   }   return 1; }       int main() {   int m,n,num,i=0,count=0;   scanf("%d %d",&m,&n);   for(num=2;1;num++)   {     if(is_prime(num))     {         i++;         if(i>=m&&i<n)         {             count++;             if(count==10)             {                 printf("%d\n",num);                 count=0;             }             else             {                 printf("%d ",num);             }         }         else if(i==n)         {             printf("%d",num);             break;         }     }   } }