40 lines
1.2 KiB
Java
40 lines
1.2 KiB
Java
|
package array;
|
|||
|
|
/**
|
|||
|
|
* 题目：238. 除自身以外数组的乘积 (productExceptSelf)
|
|||
|
|
* 描述：给你一个整数数组 nums，返回 数组 answer ，其中 answer[i] 等于 nums 中除 nums[i] 之外其余各元素的乘积 。
|
|||
|
|
* 题目数据 保证 数组 nums之中任意元素的全部前缀元素和后缀的乘积都在 32 位 整数范围内。
|
|||
|
|
* 请 不要使用除法，且在 O(n) 时间复杂度内完成此题。
|
|||
|
|
|
|||
|
|
* 链接：https://leetcode.cn/problems/product-of-array-except-self/
|
|||
|
|
*
|
|||
|
|
示例 1:
|
|||
|
|
输入: nums = [1,2,3,4]
|
|||
|
|
输出: [24,12,8,6]
|
|||
|
|
|
|||
|
|
示例 2:
|
|||
|
|
输入: nums = [-1,1,0,-3,3]
|
|||
|
|
输出: [0,0,9,0,0]
|
|||
|
|
*/
|
|||
|
|
//没做出来
|
|||
|
|
public class ProductExceptSelf {
|
|||
|
|
public int[] productExceptSelf(int[] nums) {
|
|||
|
|
int size=nums.length;
|
|||
|
|
if(size==0)
|
|||
|
|
return new int[]{};
|
|||
|
|
int[] left=new int[size],right=new int[size];
|
|||
|
|
left[0]=1;
|
|||
|
|
right[size-1]=1;
|
|||
|
|
for (int i = 1; i < size; i++) {
|
|||
|
|
left[i]=left[i-1]*nums[i-1];
|
|||
|
|
}
|
|||
|
|
for (int j = size-2; j >=0 ; j--) {
|
|||
|
|
right[j]=right[j+1]*nums[j+1];
|
|||
|
|
}
|
|||
|
|
int[]res=new int[size];
|
|||
|
|
for (int k = 0; k < size; k++) {
|
|||
|
|
res[k]=left[k]*right[k];
|
|||
|
|
}
|
|||
|
|
return res;
|
|||
|
|
}
|
|||
|
|
}
|