Use optical flow extraction on MSVD Youtube dataset

[Victoria2333]

I followed your installation steps,but I got errors like this:
CMake Error at CMakeLists.txt:12 (find_package):
By not providing "FindQt5Widgets.cmake" in CMAKE_MODULE_PATH this project
has asked CMake to find a package configuration file provided by
"Qt5Widgets", but CMake did not find one.

Could not find a package configuration file provided by "Qt5Widgets" with
any of the following names:

Qt5WidgetsConfig.cmake
qt5widgets-config.cmake

Add the installation prefix of "Qt5Widgets" to CMAKE_PREFIX_PATH or set
"Qt5Widgets_DIR" to a directory containing one of the above files. If
"Qt5Widgets" provides a separate development package or SDK, be sure it has
been installed.

-- Configuring incomplete, errors occurred!
Do I need to install Qt5.7?? I don't know how to add path to cmake.txt,would you give me some advice??
Thank you very much