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private static bool NextPermutation(int[] numList)
{
    // Find the largest index j such that a[j] < a[j + 1].
    int largestIndex = -1;
    for (int i = numList.Length - 2; i >= 0; i--)
    {
        if (numList[i] < numList[i + 1]) {
            largestIndex = i;
            break;
        }
    }

    // If no such index exists, the permutation is the last permutation.
    if (largestIndex < 0) return false;

    // Find the largest index l such that a[j] < a[l].
    int largestIndex2 = -1;
    for (int i = numList.Length - 1 ; i >= 0; i--) {
        if (numList[largestIndex] < numList[i]) {
            largestIndex2 = i;
            break;
        }
    }

    // Swap a[j] with a[l].
    int tmp = numList[largestIndex];
    numList[largestIndex] = numList[largestIndex2];
    numList[largestIndex2] = tmp;

    // Reverse the sequence from a[j + 1] up to and including the final element a[n].
    for (int i = largestIndex + 1, j = numList.Length - 1; i < j; i++, j--) {
        tmp = numList[i];
        numList[i] = numList[j];
        numList[j] = tmp;
    }

    return true;
}

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• a[j] < a[j 1].
• a[j] < a[l].
• ?? ??? ???? ??? ????? ?????.
• ??? ??? ???? a[j 1]?? ??? ???? ????? ?????.

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