When using Cinnamon desktop environment on openSUSE TW, telegram-desktop cannot
be installed. 
It seems like cinnamon-session and telegram-desktop package conflicted with
libqt5-qtstyleplugins-platformtheme-gtk2. 

Running command below will show the problem. 
sudo zypper info --requires --conflicts telegram-desktop

Information for package telegram-desktop:
-----------------------------------------
Repository     : openSUSE-Tumbleweed-Oss                                 
Name           : telegram-desktop                                        
Version        : 1.8.2-1.1                                               
Arch           : x86_64                                                  
Vendor         : openSUSE                                                
Installed Size : 43.4 MiB                                                
Installed      : Yes                                                     
Status         : up-to-date                                              
Source package : telegram-desktop-1.8.2-1.1.src                          
Summary        : Messaging application with a focus on speed and security
Description    :                                                         
    Telegram is a non-profit cloud-based instant messaging service.
    Users can send messages and exchange photos, videos, stickers, audio and
files of any type.
    Its client-side code is open-source software but the source code for recent
versions is not
    always immediately published, whereas its server-side code is closed-source
and proprietary.
    The service also provides APIs to independent developers.
Requires       : [107]                                                   
    libstdc++.so.6()(64bit)
    libstdc++.so.6(GLIBCXX_3.4)(64bit)
    libstdc++.so.6(CXXABI_1.3)(64bit)
    libm.so.6()(64bit)
    libgcc_s.so.1()(64bit)
    libgcc_s.so.1(GCC_3.0)(64bit)
    libpthread.so.0()(64bit)
    libpthread.so.0(GLIBC_2.2.5)(64bit)
    libm.so.6(GLIBC_2.2.5)(64bit)
    libgcc_s.so.1(GCC_3.3.1)(64bit)
    libstdc++.so.6(GLIBCXX_3.4.21)(64bit)
    libstdc++.so.6(CXXABI_1.3.9)(64bit)
    libglib-2.0.so.0()(64bit)
    libm.so.6(GLIBC_2.29)(64bit)
    libstdc++.so.6(GLIBCXX_3.4.9)(64bit)
    libQt5Core.so.5()(64bit)
    libQt5Core.so.5(Qt_5)(64bit)
    libQt5Core.so.5(Qt_5.13)(64bit)
    libdl.so.2()(64bit)
    libstdc++.so.6(GLIBCXX_3.4.11)(64bit)
    libstdc++.so.6(GLIBCXX_3.4.20)(64bit)
    libdl.so.2(GLIBC_2.2.5)(64bit)
    libQt5Gui.so.5()(64bit)
    libQt5Gui.so.5(Qt_5)(64bit)
    libstdc++.so.6(GLIBCXX_3.4.15)(64bit)
    libz.so.1()(64bit)
    libQt5Widgets.so.5()(64bit)
    libQt5Widgets.so.5(Qt_5)(64bit)
    libstdc++.so.6(CXXABI_1.3.8)(64bit)
    libX11.so.6()(64bit)
    libpthread.so.0(GLIBC_2.3.2)(64bit)
    librt.so.1()(64bit)
    ld-linux-x86-64.so.2()(64bit)
    ld-linux-x86-64.so.2(GLIBC_2.3)(64bit)
    libstdc++.so.6(GLIBCXX_3.4.14)(64bit)
    libcrypto.so.1.1()(64bit)
    libcrypto.so.1.1(OPENSSL_1_1_0)(64bit)
    libstdc++.so.6(GLIBCXX_3.4.18)(64bit)
    libm.so.6(GLIBC_2.27)(64bit)
    librt.so.1(GLIBC_2.2.5)(64bit)
    libQt5Network.so.5()(64bit)
    libQt5Network.so.5(Qt_5)(64bit)
    libQt5DBus.so.5()(64bit)
    libQt5DBus.so.5(Qt_5)(64bit)
    libpng16.so.16()(64bit)
    libssl.so.1.1()(64bit)
    libpthread.so.0(GLIBC_2.3.3)(64bit)
    libstdc++.so.6(CXXABI_1.3.5)(64bit)
    libGL.so.1()(64bit)
    libjpeg.so.8()(64bit)
    libstdc++.so.6(GLIBCXX_3.4.22)(64bit)
    libfreetype.so.6()(64bit)
    libpthread.so.0(GLIBC_2.12)(64bit)
    libgcc_s.so.1(GCC_4.0.0)(64bit)
    libxcb.so.1()(64bit)
    hicolor-icon-theme
    libstdc++.so.6(CXXABI_1.3.3)(64bit)
    libfontconfig.so.1()(64bit)
    liblzma.so.5()(64bit)
    libstdc++.so.6(GLIBCXX_3.4.17)(64bit)
    liblzma.so.5(XZ_5.0)(64bit)
    libavutil.so.56()(64bit)
    libavutil.so.56(LIBAVUTIL_56)(64bit)
    libXi.so.6()(64bit)
    libavcodec.so.58()(64bit)
    libavcodec.so.58(LIBAVCODEC_58)(64bit)
    libm.so.6(GLIBC_2.15)(64bit)
    libavformat.so.58()(64bit)
    libavformat.so.58(LIBAVFORMAT_58)(64bit)
    libstdc++.so.6(CXXABI_1.3.11)(64bit)
    libSM.so.6()(64bit)
    libc.so.6(GLIBC_2.25)(64bit)
    libdrm.so.2()(64bit)
    libICE.so.6()(64bit)
    libopenal.so.1()(64bit)
    openssl
    libQt5Gui.so.5(Qt_5.13.0_PRIVATE_API)(64bit)
    libxkbcommon.so.0()(64bit)
    libwebp.so.7()(64bit)
    ffmpeg
    libswscale.so.5()(64bit)
    libswscale.so.5(LIBSWSCALE_5)(64bit)
    libharfbuzz.so.0()(64bit)
    libopus.so.0()(64bit)
    libva.so.2()(64bit)
    libswresample.so.3()(64bit)
    libswresample.so.3(LIBSWRESAMPLE_3)(64bit)
    libxcb-randr.so.0()(64bit)
    libxcb-xfixes.so.0()(64bit)
    libproxy.so.1()(64bit)
    libxcb-util.so.1()(64bit)
    libxcb-xkb.so.1()(64bit)
    libxcb-keysyms.so.1()(64bit)
    libxcb-sync.so.1()(64bit)
    icu
    libxcb-shape.so.0()(64bit)
    libxcb-shm.so.0()(64bit)
    libva-drm.so.2()(64bit)
    libva-x11.so.2()(64bit)
    libxcb-render.so.0()(64bit)
    libxcb-image.so.0()(64bit)
    libxkbcommon-x11.so.0()(64bit)
    libxcb-icccm.so.4()(64bit)
    libxcb-xinerama.so.0()(64bit)
    libminizip.so.1()(64bit)
    libxcb-render-util.so.0()(64bit)
    libpcre16.so.0()(64bit)
Conflicts      : libqt5-qtstyleplugins-platformtheme-gtk2