Two Sum II (Sorted)

Read the lesson → understand the pattern → then code. Tutor works offline (built-in teacher); optional Cursor/Gemini keys upgrade chat quality.

Topic refresher: Two Pointers — Two Indices, One Rule

Move left/right based on a condition instead of checking all pairs.

int L = 0, R = n - 1;
while (L < R) {
    int sum = a[L] + a[R];
    if (sum == target) { L++; R--; }
    else if (sum < target) L++;
    else R--;
}

Medium

5/7

MediumTwo PointersLeetCode #167

Two Sum II

1-indexed sorted array. Two pointers from ends — no hash needed.

Example 1

Input

4 9
2 7 11 15

Output

1 2

Example 2

Input

3 6
2 3 4

Output

1 3

C++17Autosaves