class UsersController < ApplicationController
  before_action :signed_in_user, only: [:edit, :update]
  before_action :correct_user,   only: [:edit, :update]

  def show
    @user = User.find(params[:id])
  end

  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)
    if @user.save
      flash[:success] = "Your account has been succesfully created."
      redirect_to @user
    else
      render 'new'
    end
  end

  def edit
    @user = User.find(params[:id])
  end

  def update
    @user = User.find(params[:id])
    if @user.update_attributes(user_params)
      flash[:success] = "Profile updated"
      redirect_to @user
    else
      render 'edit'
    end
  end

  private

    def user_params
      params.require(:user).permit(:name,
                                   :email,
                                   :password,
                                   :password_confirmation)
    end

    # Before filters

    def signed_in_user
      unless signed_in?
        flash[:notice] = "Please sign in."
        redirect_to signin_url
      end
    end

    def correct_user
      @user = User.find(params[:id])
      redirect_to(root_url) unless current_user?(@user)
    end
end

class UsersController < ApplicationController
  before_action :signed_in_user, only: [:edit, :update]
  before_action :correct_user,   only: [:edit, :update]

  def show
    @user = User.find(params[:id])
  end

  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)
    if @user.save
      flash[:success] = "Your account has been succesfully created."
      redirect_to @user
    else
      render 'new'
    end
  end

  def edit
  end

  def update
    if @user.update_attributes(user_params)
      flash[:success] = "Profile updated"
      redirect_to @user
    else
      render 'edit'
    end
  end

  private

    def user_params
      params.require(:user).permit(:name,
                                   :email,
                                   :password,
                                   :password_confirmation)
    end

    # Before filters

    def signed_in_user
      unless signed_in?
        flash[:notice] = "Please sign in."
        redirect_to signin_url
      end
    end

    def correct_user
      @user = User.find(params[:id])
      redirect_to(root_url) unless current_user?(@user)
    end
end

Remove user finding from the edit and update
Remove user finding from the edit and update

Finding the correct user is now handled by the 'correct_user'
method. Removed code duplicates.
