#!/bin/sh
num_items=$1          # number of items to generate for the knapsack
weight_low=100        # low end of item weigths range
weight_high=1000000   # high end of item weights range
value_low=1           # low end of item values range
value_high=1000       # high end of item values range

echo "\ngenerating item weights (=how heavy they are)..."
w_out=/tmp/weights-${num_items}.csv
echo "weight" > ${w_out}
shuf -i ${weight_low}-${weight_high} -n ${num_items} -r >> ${w_out}

echo "\ngenerating item values (=how valuable they are)..."
v_out=/tmp/values-${num_items}.csv
echo "value" > ${v_out}
shuf -i ${value_low}-${value_high} -n ${num_items} -r >> ${v_out}

out=items-${num_items}.csv
echo "\nsaving items into \"${out}\"..."
paste -d, ${w_out} ${v_out}> ${out}

echo "Done."