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What is the difference between Linear search and Binary search?
Write a program that generates 20 random integers within the range from 0 to 100. Sort the array in descending order. Then, accepts an integer input from the user. Then, search the array using this number. Compare the performance of linear search and binary search.
这是我的代码
import java.util.Arrays;
import java.util.Scanner;
public class search {
public static void main(String args[]) {
int[] num = new int[20];
for (int i = 0; i < num.length; i++) {
num[i] = (int) (Math.random() * 101);
}
System.out.println("A list of 20 random intergers with 0 - 100");
System.out.println(Arrays.toString(num));
for (int j = 1; j < num.length; j++) {
for (int k = 0; k < num.length - 1; k++) {
if (num[k] < num[k + 1]) {
int hold = num[k + 1];
num[k + 1] = num[k];
num[k] = hold;
}
}
}
System.out.println("Array in descending order");
System.out.println(Arrays.toString(num));
Scanner input = new Scanner(System.in);
System.out.print("Enter a number to search: ");
int num2 = input.nextInt();
int loop = 0;
for ( int cnt = 0; cnt < num.length; cnt++ )
{
if ( num[cnt] == num2 )
{
loop = cnt;
System.out.println(num2+ " found");
}
}
System.out.println("Linear search - "+loop+ " loop(s)");
int loop2 = 0;
int low = 0; // low element subscript
int high = num.length - 1; // high element subscript
int middle; // middle element subscript
while ( low <= high ) {
middle = ( low + high ) / 2;
if ( num2 == num[ middle ] ) {
}
else if ( num2 > num[ middle ] )
{
low = middle +1;
loop2++;
}
else{
high = middle - 1;
loop2++;
}
}
System.out.println("Binary search - "+loop2+ " loop(s)");
}
}
我可以获得线性搜索的循环次数。但是，我无法获得二进制搜索循环数。