在Java中,去除数组中的重复元素可以通过多种方法实现,以下是几种常见的方法:
1. 使用`Set`集合去重:
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
public class RemoveDuplicates {
public static int[] removeDuplicates(int[] array) {
Set
set = new HashSet<>(); for (int num : array) {
set.add(num);
}
int[] result = new int[set.size()];
int i = 0;
for (int num : set) {
result[i++] = num;
}
return result;
}
public static void main(String[] args) {
int[] array = {1, 2, 3, 2, 4, 3, 5, 6, 4};
int[] result = removeDuplicates(array);
System.out.println("去除重复元素后的数组:");
for (int num : result) {
System.out.print(num + " ");
}
}
}
2. 使用`LinkedHashSet`保持元素顺序的去重:
import java.util.Arrays;
import java.util.LinkedHashSet;
import java.util.Set;
public class RemoveDuplicates {
public static int[] removeDuplicates(int[] array) {
Set
set = new LinkedHashSet<>(); for (int num : array) {
set.add(num);
}
int[] result = new int[set.size()];
int i = 0;
for (int num : set) {
result[i++] = num;
}
return result;
}
public static void main(String[] args) {
int[] array = {1, 2, 3, 2, 4, 3, 5, 6, 4};
int[] result = removeDuplicates(array);
System.out.println("去除重复元素后的数组:");
for (int num : result) {
System.out.print(num + " ");
}
}
}
3. 使用`Stream API`进行数组去重:
import java.util.Arrays;
import java.util.stream.Collectors;
public class RemoveDuplicates {
public static int[] removeDuplicates(int[] array) {
return Arrays.stream(array).distinct().toArray();
}
public static void main(String[] args) {
int[] array = {1, 2, 3, 2, 4, 3, 5, 6, 4};
int[] result = removeDuplicates(array);
System.out.println("去除重复元素后的数组:");
for (int num : result) {
System.out.print(num + " ");
}
}
}
4. 使用`HashMap`去重:
import java.util.HashMap;
import java.util.Map;
public class RemoveDuplicates {
public static int[] removeDuplicates(int[] array) {
Map
map = new HashMap<>(); for (int num : array) {
map.put(num, 1);
}
int[] result = new int[map.size()];
int i = 0;
for (Map.Entry
entry : map.entrySet()) { result[i++] = entry.getKey();
}
return result;
}
public static void main(String[] args) {
int[] array = {1, 2, 3, 2, 4, 3, 5, 6, 4};
int[] result = removeDuplicates(array);
System.out.println("去除重复元素后的数组:");
for (int num : result) {
System.out.print(num + " ");
}
}
}
以上方法各有优缺点,选择合适的方法取决于你对去重后数组顺序的要求以及性能考虑。如果你需要保持原始数组的顺序,可以使用`LinkedHashSet`;如果你不关心顺序,可以使用`HashSet`或`