def find_maxima(x):
    """Find local maxima of x.

    Input arguments:
    x -- 1D list of real numbers

    Output:
    idx -- list of indices of the local maxima in x
    """
    maxima = []
    for idx in range(len(x)):
        if idx == 0:
            if x[idx] >= x[idx+1]:
                maxima.append(idx)
        elif idx == len(x)-1:
            if x[idx] >= x[idx-1]:
                maxima.append(idx)
        else:
            if x[idx] >= x[idx+1] and x[idx] >= x[idx-1]:
                maxima.append(idx)
    return maxima


if __name__ == "__main__":
    values = [
    [1, 3, -2, 0, 2, 1],
    [4,2,1,3,1,5],
    [],
    [1,2,2,1],
    [1,2,2,3,1],
    ]
    for value in values:
        print(find_maxima(value))