Algorithm 1: The primary cluster-heads election

Input: all member nodes in K clusters Output: the primary cluster-heads in the set C1 ----------------------------------------------------------------------------------------------------------------- (1) For each cluster (2)     For member nodes within the same cluster (3)          Calculate the residual energy objective function $f_1(i)$, and the distance function $f_2(i)$ for each node i (4)               If the sum of energy of all nodes is greater than half of the initial energy of the network (0.5 * n$E_0$) (5)                  Calculate the value of the node adaptation function according to $P(i)$ = 1/2$*f_1(i)$ + ½ * $f_2(i)$ (6)               Else (7)                  Calculate the value of the node adaptation function according to $P(i)$ = $\frac{E_{res}\left(i\right)}{E_0}*f_1(i)$ + (1 −$\frac{E_{res}\left(i\right)}{E_0}$) * $f_2(i)$ (8)       Find the node with the largest fitness function value and save this node information in the set C1 (9) End