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          "value": "\\min \\sum_i \\sum_j C_{i,j} X_{i,j}"
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              "value": "for sparse inputs"
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  "references": [
    ".. [1] https://en.wikipedia.org/wiki/Assignment_problem",
    "",
    ".. [2] DF Crouse. On implementing 2D rectangular assignment algorithms.",
    "       *IEEE Transactions on Aerospace and Electronic Systems*,",
    "       52(4):1679-1696, August 2016, :doi:`10.1109/TAES.2016.140952`"
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