Algorithm 3 (Bisection algorithm to solve P5)

Require: Initialize $u_l$ and $u_u$, set ${ϵ}_3>0$.   repeat       1. Set $u=(u_l+u_u)/2$.       2. Compute $\widehat{\mathbf{s}}\left(u\right)$ via Algorithm 2       3. If $f(\widehat{\mathbf{s}}\left(u\right)/u)\ge 0$, set $u_l=u$, otherwise set $u_u=u$.   until$|u_u-u_l|\le {ϵ}_3$.   4. Output $\widehat{\mathbf{s}}\left(u\right)\to \mathbf{Q}$.