2505-BitwiseOROfAllSubsequenceSums.go

package main

// 2505. Bitwise OR of All Subsequence Sums
// Given an integer array nums, return the value of the bitwise OR of the sum of all possible subsequences in the array.

// A subsequence is a sequence that can be derived from another sequence by removing zero 
// or more elements without changing the order of the remaining elements.

// Example 1:
// Input: nums = [2,1,0,3]
// Output: 7
// Explanation: All possible subsequence sums that we can have are: 0, 1, 2, 3, 4, 5, 6.
// And we have 0 OR 1 OR 2 OR 3 OR 4 OR 5 OR 6 = 7, so we return 7.

// Example 2:
// Input: nums = [0,0,0]
// Output: 0
// Explanation: 0 is the only possible subsequence sum we can have, so we return 0.

// Constraints:
//     1 <= nums.length <= 10^5
//     0 <= nums[i] <= 10^9

import "fmt"

func subsequenceSumOr(nums []int) int64 {
    res, sum := 0, 0
    for _, v := range nums {
        res |= v
        sum += v
        res |= sum
    }
    return int64(res)
}

func main() {
    // Example 1:
    // Input: nums = [2,1,0,3]
    // Output: 7
    // Explanation: All possible subsequence sums that we can have are: 0, 1, 2, 3, 4, 5, 6.
    // And we have 0 OR 1 OR 2 OR 3 OR 4 OR 5 OR 6 = 7, so we return 7.
    fmt.Println(subsequenceSumOr([]int{2,1,0,3})) // 7
    // Example 2:
    // Input: nums = [0,0,0]
    // Output: 0
    // Explanation: 0 is the only possible subsequence sum we can have, so we return 0.
    fmt.Println(subsequenceSumOr([]int{0,0,0})) // 0
}