ProductExceptSelfByPrefixSuffixMultiplication.java

class Solution {
    public int[] productExceptSelf(int[] nums) {
        int n = nums.length;
        int[] ans = new int[n];
        Arrays.fill(ans, 1);
        for(int i = 1; i< n; i++) {
            ans[i] = ans[i-1] *nums[i-1]; // calculating prefix
        }
        int curr = 1;
        for(int j = n-1; j>=0; j--) {
            ans[j] *= curr; // multiplying by suffix
            curr*=nums[j]; // updating curr with suffix for the next iteration 
        }
        return ans;
    }
}