class Solution {
public:
    vector<int> productExceptSelf(vector<int>& nums) {
        int size = nums.size();
        vector<int> ans(size, 1);

        for(int i=1;i<size;i++)
            ans[i] = ans[i-1] * nums[i-1];
        for(int i=size-2; i>=0; i--)
            nums[i] = nums[i+1] * nums[i];
        for(int i=0;i<size-1;i++)
            ans[i] = ans[i] * nums[i+1];
        return ans;
    }
};