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    "# specifying the knapsack instance\n",
    "\n",
    "import numpy as np\n",
    "from __future__ import division\n",
    "import os\n",
    "import time\n",
    "\n",
    "# reading in knapsack instance:\n",
    "numOfItems = 10\n",
    "instanceNumber = 3\n",
    "filename = 'C://users/dimo/desktop/teaching/Saclay2015/introToOptimization/02-dynProgAndBranchBound/knapsackinstances/KP-random-%ditems-%d.txt' % (numOfItems, instanceNumber)\n",
    "w = []\n",
    "p = []\n",
    "with open(filename, \"r\") as text_file:\n",
    "        for line in text_file:\n",
    "            ll = line.split()\n",
    "            if 'W' in ll[0]:\n",
    "                W = int(ll[2])\n",
    "            if 'n' not in ll[0] and 'W' not in ll[0]:\n",
    "                w.append(int(ll[0]))\n",
    "                p.append(int(ll[1]))\n",
    "\n",
    "# and its objective and constraint functions:\n",
    "def f(x):   # objective function\n",
    "    return np.sum(p*x)\n",
    "\n",
    "def g(x):   # constraint violation function\n",
    "    return np.sum(w*x) - W"
   ]
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