We show that there is a novel and simple decomposition of an input point set P into small subsets P_i, such that:
We show that there is a novel and simple decomposition of an input point set P into small subsets P_i, such that:
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1- the cost of solving the facility location problem for each P_i is small (which means that for each P_i one needs to open only a small, polylogarithmic number of facilities),
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1- the cost of solving the facility location problem for each P_i is small (which means that for each P_i one needs to open only a small, polylogarithmic number of facilities),
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2- sum_i opt(P_i) \le (1+eps) opt(P), where for a point set P, opt(P) denotes the cost of an optimal solution for P.
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2- sum_i opt(P_i) \le (1+eps) opt(P), where for a point set P, opt(P) denotes the cost of an optimal solution for P.
Using this decomposition we obtain two main results:
Using this decomposition we obtain two main results: