为什么3sum算法只查看特定数字右侧的子数组？

def three_sum(nums, target):
    nums.sort()
    result = []
    n = len(nums)
    
    for i in range(n - 2):
        if i > 0 and nums[i] == nums[i - 1]:
            continue
        left, right = i + 1, n - 1
        while left < right:
            current_sum = nums[i] + nums[left] + nums[right]
            if current_sum == target:
                result.append([nums[i], nums[left], nums[right]])
                while left < right and nums[left] == nums[left + 1]:
                    left += 1
                while left < right and nums[right] == nums[right - 1]:
                    right -= 1
                left += 1
                right -= 1
            elif current_sum < target:
                left += 1
            else:
                right -= 1
    
    return result

# 示例用法
nums = [-1, 0, 1, 2, -1, -4]
target = 0
print(three_sum(nums, target))