Week 2 @ 2025 算法周记【nSum + 双指针数组】

func twoSum(nums []int, target int) []int {
    contains := make(map[int]int, len(nums))
    for i, num := range nums {
        contains[num] = i
    }

    for j, num := range nums {
        if i, exist := contains[target-num]; i != j && exist {
            return []int{i, j}
        }
    }

    return nil
}

func twoSum(nums []int, target int) []int {
    sort.Ints(nums)

    i, j := 0, len(nums)-1
    for i < j {
        sum := nums[i] + nums[j]
        if sum = target {
            return []int{nums[i], nums[j]}
        } else if sum < target {
            i++
        } else {
            j--
        }
    }

    return nil
}