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August 31, 2015 23:44
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Product of Array Except Self
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/* | |
Given an array of n integers where n > 1, nums, return an array output such that output[i] is equal to the product of all the elements of nums except nums[i]. | |
Solve it without division and in O(n). | |
For example, given [1,2,3,4], return [24,12,8,6]. | |
Follow up: | |
Could you solve it with constant space complexity? (Note: The output array does not count as extra space for the purpose of space complexity analysis.) | |
*/ | |
public class Solution { | |
public int[] productExceptSelf(int[] nums) { | |
int[] result = new int[nums.length]; | |
result[0] = 1; | |
for(int i = 1; i < nums.length; i++) { | |
result[i] = nums[i-1] * result[i-1]; | |
} | |
int right = 1; | |
for(int i = nums.length -1; i >= 0; i--) { | |
result[i] = right * result[i]; | |
right *= nums[i]; | |
} | |
return result; | |
} | |
} |
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but this is O(2n) ?