// LLP form of Johnson reweighting: raise prices G[j] until every reduced edge weight is non-negative.

class LLPJohnson {
  int[] LLPJohnson(set<int>[] pre, int[][] w) {
    int[] G = 0;
    forbidden (j) :
      exists i in pre[j] : G[j] < G[i] - w[i][j]
    =>
      advance :
        forall k in [0..n] :
          G[k] = max(G[k], max i in pre[k] : G[i] - w[i][k]);
    return G;
  }
}