第十四届蓝桥杯集训——练习解题阶段(无序阶段)-ALGO-51算法训练 Torry的困惑(基本型)

#include<stdio.h>
int pr[100010];
int top;
int isPrime(int n)
{
  int i;
  for(i = 0; i < top; i++)
  {
    if(n % pr[i] == 0)
    {
      return 0;
    }
  }
  return 1;
}
int findNextPrime(void)
{
  int n = pr[top - 1] + 1;
  while(!isPrime(n))
  {
    n++;
  }
  pr[top++] = n;
  return n;
}
int main(void)
{
  int i, n;
  int result = 2;
  scanf("%d", &n);
  pr[0] = 2;
  top = 1;
  for(i = 1; i < n; i++)
  {
    int x = findNextPrime();
    result *= x;
    result %= 50000;
  }
  printf("%d", result);
  return 0;
}

#include <iostream>
using namespace std;
int a[100005];
int main()
{
  unsigned int i, j, n, cnt = 1, cj = 2;
  cin >> n;
  if (n == 1)
  {
    cout << 2 << endl;
    return 0;
  }
  a[0] = 2;
  for (i = 3; i < 2000000; i++)
  {
    for (j = 0; j < cnt; j++)
    {
      if (a[j] * a[j] > i)
      {
        break;
      }
      else
      {
        if (!(i % a[j]))
        {
          break;
        }
      }
    }
    if (a[j] * a[j] > i)
    {
      a[cnt++] = i;
      cj = (cj % 50000) * (i % 50000) ;
      if (cnt == n)
      {
        break;
      }
    }
  }
  cout << cj % 50000 << endl;
  return 0;
}

import java.io.*;
public class Main {
  public static void main(String[] args) {
    try{
      BufferedReader br = new BufferedReader(new InputStreamReader(System.in),1);
      String line = br.readLine();
      int n = Integer.parseInt(line);
      getans(n);
    }catch(Exception e){
      System.out.println("Message:"+e.getMessage());
    }   
  }
  
  public static void getans(int n){
    if(n<1);
    else if(n==1)System.out.println(2);
    else if(n<7){
      long ans = 6,nowp = 3;
      for(int i=0;i<n-2;i++){
        nowp=nextprime(nowp);
        ans*=nowp;
      }
      System.out.println(ans);
    }else if(n==7)System.out.println(10510);
    else if(n<100){
      long ans = 10510,nowp = 17;
      for(int i=0;i<n-7;i++){
        nowp=nextprime(nowp);
        ans=ans*nowp%50000;
      }
      System.out.println(ans);
    }else if(n==100)System.out.println(31090);
    else if(n<1000){
      long ans = 31090,nowp = 541;
      for(int i=0;i<n-100;i++){
        nowp=nextprime(nowp);
        ans=ans*nowp%50000;
      }
      System.out.println(ans);
    }else if(n==1000)System.out.println(1570);
    else if(n<=10000){
      long ans = 1570,nowp = 7919;
      for(int i=0;i<n-100;i++){
        nowp=nextprime(nowp);
        ans=ans*nowp%50000;
      }
      System.out.println(ans);
    }else if(n==10000)System.out.println(48410);
    else if(n<100000){
      long ans = 48410,nowp = 115321;
      for(int i=0;i<n-100;i++){
        nowp=nextprime(nowp);
        ans=nowp%50000*ans%50000;
      }
      System.out.println(ans);
    }else if(n==100000)System.out.println(20710);
    else{
      long ans = 20710,nowp = 1452433;
      for(int i=0;i<n-100;i++){
        nowp=nextprime(nowp);
        ans=nowp%50000*ans%50000;
      }
      System.out.println(ans);
    }
  }
  
  public static long nextprime(long now){
    now+=2;
    int check = 0;
    while(true){
      check = checkprime(now);
      if(check==0)
        now+=2;
      else
        break;
    }
    return now;
  }
  
  public static int checkprime(long n){
    for(int i=3;i<=Math.sqrt(n);i+=2)
      if(n%i==0)return 0;
    return 1;
  }
  
}

n=eval(input())
num=1
i=2
count=0
while True:
    flag=0
    for j in range(2,i):
        if i%j==0:
            flag=1
            break
    if flag==0:
        count+=1
        if num>50000:
            num%=50000
        num*=i
    if count==n:
        print(num%50000)
        break
    i+=1