September 2017 Update

Task/Knapsack-problem-Continuous/Phix/knapsack-problem-continuous.phix

@@ -0,0 +1,30 @@
+constant meats = {
+--Item  Weight (kg)     Price (Value)
+{"beef",    3.8,    36},
+{"pork",    5.4,    43},
+{"ham",     3.6,    90},
+{"greaves", 2.4,    45},
+{"flitch",  4.0,    30},
+{"brawn",   2.5,    56},
+{"welt",    3.7,    67},
+{"salami",  3.0,    95},
+{"sausage", 5.9,    98}}
+
+function by_weighted_value(integer i, j)
+    atom {?,weighti,pricei} = meats[i],
+         {?,weightj,pricej} = meats[j]
+    return compare(pricej/weightj,pricei/weighti)
+end function
+
+sequence tags = custom_sort(routine_id("by_weighted_value"),tagset(length(meats)))
+
+atom w = 15, worth = 0
+for i=1 to length(tags) do
+    object {desc,wi,price} = meats[tags[i]]
+    atom c = min(wi,w)
+    printf(1,"%3.1fkg%s of %s\n",{c,iff(c=wi?" (all)":""),desc})
+    worth += (c/wi)*price
+    w -= c
+    if w=0 then exit end if
+end for
+printf(1,"Total value: %f\n",{worth})