Two sum · sorted

Find two values in ascending data whose sum equals a target by moving pointers inward.

Remember: Too small: move left. Too large: move right.

Example: [2,7,11,15], target 9 → indices [0,1].

Time: O(n). Auxiliary space: O(1).

Formula: sum = a[left] + a[right]

Ascending input is required. Return zero-based indices of one pair.

Complexities describe the underlying algorithm; tutorial snapshots and rendering can use additional resources.

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