~/private/perl$ shrink 100
Before:
#0: -------------------- (20)
#1: --- (3)
#2: ------------------------- (25)
#3: ---------- (10)
#4: --- (3)
#5: ------------------------ (24)
#6: ------------------------- (25)
Weight 110, target 100

Sorted:
#0: ------------------------- (25)
#1: ------------------------- (25)
#2: ------------------------ (24)
#3: -------------------- (20)
#4: ---------- (10)
#5: --- (3)
#6: --- (3)
Weight 110, target 100

Reduce bags #0-#1 by 1 to weight of next_heaviest, 24:
#0: ------------------------ (24)
#1: ------------------------ (24)
#2: ------------------------ (24)
#3: -------------------- (20)
#4: ---------- (10)
#5: --- (3)
#6: --- (3)
Weight 108, target 100

Finally, reduce bags #0-#2 to target weight of 100:
#0: ---------------------- (22)
#1: --------------------- (21)
#2: --------------------- (21)
#3: -------------------- (20)
#4: ---------- (10)
#5: --- (3)
#6: --- (3)
Weight 100, target 100

After:
#0: -------------------- (20)
#1: --- (3)
#2: ---------------------- (22)
#3: ---------- (10)
#4: --- (3)
#5: --------------------- (21)
#6: --------------------- (21)
Weight 100, target 100