Problems from Waterloo Programming Contest 2010-07-10

Submissions Users
Name   Total Acc. Ratio Fastest Total Acc. Ratio Difficulty
Ideas 50 6 12% 0.18 9 5 56% 7.5
Shopping 757 145 19% 0.15 83 68 82% 6.8
Stack Machine 74 20 27% 0.02 14 10 71% 6.6
Tunnelling the Earth 73 40 55% 0.00 33 28 85% 4.8