Given an integer array nums
, find the contiguous subarray within an array (containing at least one number) which has the largest product.
Example 1:
Input: [2,3,-2,4] Output: 6 Explanation: [2,3] has the largest product 6.
Example 2:
Input: [-2,0,-1] Output: 0 Explanation: The result cannot be 2, because [-2,-1] is not a subarray.
方法1:
package leetcode;
import org.junit.Test;
/**
* @author zhangyu
* @version V1.0
* @ClassName: ProductSubarray
* @Description: zhangyu
* @date 2018/12/24 11:14
**/
public class ProductSubarray {
@Test
public void fun() {
int nums[] = {2, 3, -2, 4};
int product = maxProduct(nums);
System.out.println(product);
}
private int maxProduct(int[] nums) {
int max = nums[0];
int min = nums[0];
int result = nums[0];
for (int i = 1; i < nums.length; i++) {
int temp = max;
max = Math.max(Math.max(max * nums[i], min * nums[i]), nums[i]);
min = Math.min(Math.min(temp * nums[i], min * nums[i]), nums[i]);
if (max > result) {
result = max;
}
}
return result;
}
}
时间复杂度:O(n)
空间复杂度:O(1)
源码github地址:https://github.com/zhangyu345293721/leetcode