学习用Java进行调试
我正在学习在Netbeans上使用JPDA,并解决Sphere的在线判断问题 我一直在读关于他JPDA的书,但没发现有什么帮助 此代码基于starblue提供的Eratostenes实现筛选,运行方式如下:学习用Java进行调试,java,debugging,netbeans,jpda,Java,Debugging,Netbeans,Jpda,我正在学习在Netbeans上使用JPDA,并解决Sphere的在线判断问题 我一直在读关于他JPDA的书,但没发现有什么帮助 此代码基于starblue提供的Eratostenes实现筛选,运行方式如下: 2 1 10 //here the primes between 1 and 10 should print 3 5 //here the primes between 3 and 5 should print package sphere; /** * * @author
2
1 10
//here the primes between 1 and 10 should print
3 5
//here the primes between 3 and 5 should print
package sphere;
/**
*
* @author Administrator
*/
//import java.util.ArrayList;
import java.util.BitSet;
import java.lang.Math.*;
import java.util.ArrayList;
public class Main
{
public static int ApproximateNthPrime(int nn)
{
double n = (double)nn;
double p;
if (nn >= 7022)
{
p = n * Math.log(n) + n * (Math.log(Math.log(n)) - 0.9385);
}
else if (nn >= 6)
{
p = n * Math.log(n) + n * Math.log(Math.log(n));
}
else if (nn > 0)
{
p = new int[] { 2, 3, 5, 7, 11 }[nn - 1];
}
else
{
p = 0;
}
return (int)p;
}
// Find all primes up to and including the limit
public static BitSet SieveOfEratosthenes(int limit)
{
final BitSet primes = new BitSet();
primes.set(0,false);
primes.set(1,false);
primes.set(2,limit,true);
for (int i =0; i*i<limit;i++)
{
if (primes.get(i))
{
for (int j=i*1; j<limit;j+=1)
{
primes.clear(j);// hace que el indice j sea false (no primo)
}
}
}
return primes;
}
public static ArrayList<Integer> GeneratePrimesSieveOfEratosthenes(int n)
{
int limit = ApproximateNthPrime(n);
BitSet bits = SieveOfEratosthenes(limit);
ArrayList <Integer> primes = new ArrayList<Integer>();
for (int i = 0, found = 0; i < limit && found < n; i++)
{
if (bits.get(i))
{
primes.add(i);
found++;
}
}
return primes;
}
public static void main (String[] args) throws java.lang.Exception
{
java.io.BufferedReader r = new java.io.BufferedReader (new java.io.InputStreamReader (System.in));
String s;
s= r.readLine();
int test_cases = Integer.parseInt(s);
int case_counter =0;
while (case_counter<test_cases) {
// System.out.println(s);
s = r.readLine();
String [] splitted = s.split(" ");
int lower_bound = Integer.parseInt(splitted[0]);
int upper_bound = Integer.parseInt(splitted[1]);
ArrayList <Integer> primesList= GeneratePrimesSieveOfEratosthenes(upper_bound);
for (int i =0; i<primesList.size();i++){
if (primesList.get(i)<=lower_bound)System.out.println(primesList.get(i));
}
case_counter++;
System.out.println(" "); // space that separates test cases
}
}
}
但我不确定我是否能够通过这种方式获得有意义的信息。以下是我得到的屏幕:
我不知道如何从中获得有用的信息
我的问题是:
a)我想在primes位集通过此循环时观察它。
我该怎么做?
b)此代码到底有什么问题?
您是如何使用调试器发现它的?
请提及一步一步的过程。因此,我提取了以下方法:
private static void printPrimes(int lower_bound, int upper_bound) {
ArrayList<Integer> primesList = GeneratePrimesSieveOfEratosthenes(upper_bound);
for (int i = 0; i < primesList.size(); i++) {
if (primesList.get(i) <= lower_bound)
System.out.println(primesList.get(i));
}
}
私有静态void打印素数(int下界,int上界){
ArrayList primesList=生成时间优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权优先权(上限);
对于(int i=0;iprimes.get(j)==false
private static void printPrimes(int lower_bound, int upper_bound) {
ArrayList<Integer> primesList = GeneratePrimesSieveOfEratosthenes(upper_bound);
for (int i = 0; i < primesList.size(); i++) {
if (primesList.get(i) <= lower_bound)
System.out.println(primesList.get(i));
}
}