Try to write pseudocode for the tree structured global sum illustrated in fig $1\mathrm{.}1.$ Assume the number of cores is a power of two $(1,2,4,8,...).$ hints: use a variable divisor to determine whether a core should send its sum or receive and add. The divisor should start with the value $2$ and be doubled after each iteration. Also use a variable core$\_$difference to determine which core should be partnered with the current core. It should start with the value $1$ and also be doubled after each iteration. For example, in the first iteration $0\%$ divisor $=0$ and $1\%$ divisor $=1$ so $0$ receives an adds, while $1$ sends. Also in the first iteration $0+$ core$\_$difference $=1$ and $1-$ core$\_$difference $=0$ so $0$ and $1$ are paired in the first iteration