LC.P167[两数之和II-输入有序数组]

方法一：双指针

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class Solution {
    public int[] twoSum(int[] numbers, int target) {
        int l = 0, r = numbers.length - 1;
        while (l < r) {
            int sum = numbers[l] + numbers[r];
            if (sum < target) ++l;
            else if (sum > target) --r;
            else return new int[]{l + 1, r + 1};
        }
        return new int[]{};
    }
}
  • 时间复杂度：$O(n)$
  • 空间复杂度：$O(1)$