Java数组排序和查找

时间:2023-03-09 06:49:16
Java数组排序和查找

Java 1.2 添加了自己的一套实用工具,可用来对数组或列表进行排列和搜索。这些工具都属于两个新类的“静态”方法。这两个类分别是用于排序和搜索数组的Arrays,以及用于排序和搜索列表的Collections。

/**
* Created by Frank
*/
public class Array1 {
static Random r = new Random();
static char[] src = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".toCharArray(); // Create a random String
public static String randString(int length) {
char[] buf = new char[length];
int rnd;
for (int i = 0; i < length; i++) {
rnd = Math.abs(r.nextInt()) % src.length;
buf[i] = src[rnd];
}
return new String(buf);
} // Create a random array of Strings
public static String[] randStrings(int length, int size) {
String[] s = new String[size];
for (int i = 0; i < size; i++) {
s[i] = randString(length);
}
return s;
} public static void print(byte[] b) {
for (byte aB : b) {
System.out.println(aB + " ");
}
System.out.println();
} public static void print(String[] s) {
for (String value : s) {
System.out.print(value + " ");
}
System.out.println();
} public static void main(String[] args) {
byte[] b = new byte[15];
r.nextBytes(b);
print(b);
java.util.Arrays.sort(b);
print(b);
int loc = Arrays.binarySearch(b, b[10]);
System.out.println("Location of " + b[10] + " = " + loc);
String[] s = randStrings(4, 10);
print(s);
Arrays.sort(s);
print(s);
loc = Arrays.binarySearch(s, s[4]);
System.out.println("Location of " + s[4] + " = " + loc);
}
}