Medium
Product of Array Except Self — C++
Full explanation · Time O(n) · Space O(1)
// Time: O(n)
// Space: O(1)
class Solution {
public:
vector<int> productExceptSelf(vector<int>& nums) {
if (nums.empty()) {
return {};
}
vector<int> left_product(nums.size());
left_product[0] = 1;
for (int i = 1; i < nums.size(); ++i) {
left_product[i] = left_product[i - 1] * nums[i - 1];
}
int right_product = 1;
for (int i = static_cast<int>(nums.size()) - 2; i >= 0; --i) {
right_product *= nums[i + 1];
left_product[i] = left_product[i] * right_product;
}
return left_product;
}
};