最大乘积
题目描述
给定一个无序数组,包含正数、负数和0,要求从中找出3个数的乘积,使得乘积最大,要求时间复杂度:O(n),空间复杂度:O(1)
输入描述:4 1 3 2
无序整数数组A[n]
输出描述:24
满足条件的最大乘积
public class Zdcd {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int n=scanner.nextInt();
long arr[] = new long[n];
for (int i = 0; i <n; i++) {
arr[i] = scanner.nextInt();
}
Arrays.sort(arr);
long max01 = arr[arr.length - 1];
long max02 = arr[arr.length - 2];
long max03 = arr[arr.length - 3];
long min01 = arr[0];
long min02 = arr[1];
if((min01<0&&min02<0)&&(max03<0)&&(max02>0)) {
System.out.println(min01*min02*max01);
}
else if((min01<0&&min02<0)&&(max03>0)) {
if(min01*min02>max02*max03) {
System.out.println(min01*min02*max01);
}
else {
System.out.println(max01 * max02 * max03);
}
}
else {
if (min01 > 0||(min01<0&&min02>0)||max01<0) {
System.out.println(max01 * max02 * max03);
}
}
}
}