K-coverage in wireless sensor networks (WSNs) is defined as ensuring that every point in the area is monitored by at least K different sensor nodes. In this paper, we propose a new K-coverage algorithm for sensor networks, called Randomly Ordered Activation and Layering (ROAL), that solves the K-coverage problem in a small constant time in a distributed manner while providing simple and efficient dynamic reconfiguration for the WSNs. The simulation results show that the ROAL can guarantee K-coverage with the uncovered area less than 5% when a sufficient number of sensor nodes are provided, and that the lifetime of the sensor network is significantly extended by more than 400%