Which of the following reactions are disproportionation reactions?

$\left(\mathrm{i}\right) 2{\mathrm{Cu}}^{+}⟶{\mathrm{Cu}}^{2+}+{\mathrm{Cu}}^0$

$\left(ii\right) 3{\mathrm{MnO}}_4^{2-}+4{\mathrm{H}}^{+}⟶2{\mathrm{MnO}}_4^{-}+{\mathrm{MnO}}_2+2{\mathrm{H}}_2\mathrm{O}$

$\left(iii\right) 2{\mathrm{KMnO}}_4\stackrel{\Delta }{⟶}{\mathrm{K}}_2{\mathrm{MnO}}_4+{\mathrm{MnO}}_2+{\mathrm{O}}_2$

$\left(\mathrm{iv}\right) 2{\mathrm{MnO}}_4^{-}+3{\mathrm{Mn}}^{2+}+2{\mathrm{H}}_2\mathrm{O}⟶5{\mathrm{MnO}}_2+4{\mathrm{H}}^{+}$