\[ y'(x)-\sqrt {| y(x)| }=0 \] ✓ Mathematica : cpu = 0.0633034 (sec), leaf count = 26
DSolve[-Sqrt[Abs[y[x]]] + Derivative[1][y][x] == 0,y[x],x]
\[\left \{\left \{y(x)\to \text {InverseFunction}\left [\int _1^{\text {$\#$1}}\frac {1}{\sqrt {| K[1]| }}dK[1]\& \right ][x+c_1]\right \}\right \}\] ✓ Maple : cpu = 0.09 (sec), leaf count = 31
dsolve(diff(y(x),x)-abs(y(x))^(1/2) = 0,y(x))
\[x -\left (\left \{\begin {array}{cc}-2 \sqrt {-y \left (x \right )} & y \left (x \right )\le 0 \\ 2 \sqrt {y \left (x \right )} & 0<y \left (x \right ) \end {array}\right .\right )+c_{1} = 0\]