Topic 1040:prime Number

Topic 1040:prime Number

time limit:1 seconds

Memory limit:32 MB

Special question: No

Title Description:

Output the k-th prime number.

Input:

k≤10000

Output:

The k-th prime number.

Sample input:

37

Sample output:

517
Thinking of solving problems: prime Selection method
Note: The title requirement is the output 1000 in any one prime, the size of the array declared as 1000 is far from enough, the program running results show the 1000th prime number is 7919, so the array to declare a larger point.
First commit because the array is small  

#include <iostream>#include<stdio.h>#include<string.h>#include<algorithm>#include<stack>#include<math.h>using namespacestd;# define Len200000intPrime[len];//used to store prime numbersintPrimesize;//number of vegetarian charactersBOOLMark[len];//Mark whether a number is primevoidinit () {primesize=0;//Number of characters initialized to 0    Long Long inti,j;  for(i=0; i<len; i++) {Mark[i]=false;//true to indicate that it is not a prime number    }     for(i=2; i<len; i++)    {        if(mark[i]==true)Continue;//not primes continue        Else{prime[primesize++]=i;  for(J=i*i; j<len; j+=i) {mark[j]=true; }        }    }}intMain () {init (); intN;  while(SCANF ("%d", &n)! =EOF) {printf ("%d\n", prime[n-1]); }    return 0;}

Topic 1040:prime Number