task1.ts

function findUniquePairs(arr: number[], target: number): number[][] {
    if (arr.length < 2) return [];

    const result: number[][] = [];
    const nums = [...arr].sort((a, b) => a - b);

    let left = 0;
    let right = nums.length - 1;

    while (left < right) {
        const sum = nums[left] + nums[right];

        if (sum === target) {
            result.push([nums[left], nums[right]]);

            // Skip duplicates
            const leftValue = nums[left];
            const rightValue = nums[right];

            while (left < right && nums[left] === leftValue) left++;
            while (left < right && nums[right] === rightValue) right--;

        } else if (sum < target) {
            left++;
        } else {
            right--;
        }
    }

    return result;
}