Problems by Greg Hamerly

Submissions Users
Name   Total Acc. Ratio Fastest Total Acc. Ratio Difficulty
Adding Words 17070 4279 25% 0.00 3908 3080 79% 3.6
Add Two Numbers 9588 6042 63% 0.00 5572 5346 96% 1.3
All Different Directions 1890 914 48% 0.00 866 782 90% 2.3
Bag of Tiles 1550 444 29% 0.08 279 217 78% 6.2
BASIC Interpreter 2075 432 21% 0.01 382 272 71% 5.7
Birthday Paradox 243 91 37% 0.00 85 72 85% 5.3
Bounding Robots 2970 1763 59% 0.00 1677 1593 95% 1.6
Cellular Merging 89 11 12% 0.01 14 5 36% 8.3
Charting Progress 3139 1441 46% 0.00 1246 1147 92% 2.1
Chatter 352 164 47% 0.15 109 98 90% 4.4
Checking For Correctness 2042 640 31% 0.01 554 456 82% 3.8
Connect the Dots 1337 502 38% 0.00 469 407 87% 3.8
Convex Polygon Area 1850 1177 64% 0.00 1045 993 95% 1.8
Counting Stars 14398 4153 29% 0.00 2960 2504 85% 3.1
Dart Scoring 711 268 38% 0.00 233 193 83% 4.4
Das Blinkenlights 6509 3016 46% 0.00 2598 2434 94% 1.7
Deduplicating Files 3996 1206 30% 0.01 1098 843 77% 4.3
Detailed Differences 14096 7521 53% 0.00 6723 6490 97% 1.4
Different Distances 5490 2832 52% 0.00 2635 2484 94% 1.6
Echo Echo Echo 11218 6756 60% 0.00 6109 5907 97% 1.3
Engineering English 6233 2876 46% 0.00 2690 2329 87% 2.1
Enlarging Hash Tables 3308 1089 33% 0.00 815 691 85% 3.3
Erdős Numbers 1049 314 30% 0.01 280 211 75% 5.1
Escape Plan 1013 283 28% 0.01 245 183 75% 5.7
Estimating the Area of a Circle 6309 3772 60% 0.00 3566 3396 95% 1.5
Forest Fires 194 81 42% 0.18 69 56 81% 5.2
Functional Fun 1738 801 46% 0.00 703 664 94% 1.9
Fundamental Neighbors 1212 480 40% 0.00 399 323 81% 4.4
Generalized Recursive Functions 922 354 38% 0.02 280 235 84% 4.4
Genetic Search 1343 751 56% 0.00 645 596 92% 2.1
Gerrymandering 3117 2020 65% 0.00 1831 1761 96% 1.6
Golomb Rulers 1149 599 52% 0.02 532 478 90% 3.0
Hall O' Wee Mirrors 218 91 42% 0.00 90 69 77% 5.5
Heliocentric 2973 1711 58% 0.00 1521 1429 94% 1.8
Hitting the Targets 2572 1557 61% 0.00 1502 1411 94% 1.6
How Many Digits? 7458 2118 28% 0.00 1786 1410 79% 3.7
Hurricane Danger! 884 250 28% 0.00 268 199 74% 5.0
Image Decoding 2759 749 27% 0.00 694 568 82% 3.3
Island Hopping 3108 1479 48% 0.02 1019 912 89% 2.8
Juggling Patterns 727 200 28% 0.00 171 129 75% 6.0
Limited Correspondence 1113 224 20% 0.03 136 87 64% 7.3
Loopy Cab Drivers 452 125 28% 0.01 102 87 85% 5.8
Loopy Transit 242 140 58% 0.00 143 123 86% 3.8
Managing Packaging 746 267 36% 0.01 245 163 67% 5.7
Mandelbrot 3532 1058 30% 0.00 965 836 87% 3.0
Matrix Inverse 3546 1294 36% 0.00 1268 1077 85% 2.9
Maximizing (And Minimizing) Your Winnings 886 363 41% 0.07 286 242 85% 4.1
Maximizing Your Pay 497 157 32% 0.00 140 104 74% 5.3
Maze Movement 813 440 54% 0.06 303 269 89% 3.7
Metaprogramming 3290 1474 45% 0.00 1333 1198 90% 2.1
Missing Numbers 7733 4203 54% 0.00 3818 3573 94% 1.7
Multi-Touch Gesture Classification 128 31 24% 0.00 31 23 74% 7.2
Musical Notation 1418 737 52% 0.00 705 662 94% 1.9
Music Your Way 1808 921 51% 0.00 823 749 91% 2.2
Name That Permutation 802 337 42% 0.00 307 261 85% 4.3
Notable Quotables 125 21 17% 0.00 31 17 55% 7.2
Oddities 35987 19590 54% 0.00 17292 16627 96% 1.4
Out of Context 32 10 31% 0.04 13 7 54% 8.0
Pachinko Probability 449 174 39% 0.00 179 146 82% 5.7
Pachyderm Peanut Packing 1022 673 66% 0.00 593 558 94% 1.9
Page Layout 827 237 29% 0.02 157 131 83% 5.0
Parallel Analysis 448 210 47% 0.08 128 110 86% 4.1
Parsing Hex 3109 1026 33% 0.00 982 864 88% 2.5
Permutation Encryption 4754 1765 37% 0.00 1700 1483 87% 2.4
Polish Notation 1811 539 30% 0.00 445 372 84% 3.2
Preludes 2466 1329 54% 0.00 1292 1216 94% 1.8
Primal Representation 2047 608 30% 0.02 499 397 80% 5.1
Prime Reduction 3457 1237 36% 0.03 843 711 84% 3.7
Prime Spiral 742 318 43% 0.00 236 212 90% 3.2
Quick Estimates 12824 7250 57% 0.00 6770 6437 95% 1.5
Quite a Problem 4705 2012 43% 0.00 1895 1720 91% 2.1
Race Day 473 204 43% 0.00 173 145 84% 3.8
Reachable Roads 4044 2045 51% 0.00 1643 1500 91% 2.3
Reversing Roads 2694 640 24% 0.00 555 438 79% 4.5
Robot Protection 1656 739 45% 0.02 453 412 91% 2.6
Saving Daylight 2867 1577 55% 0.00 1513 1388 92% 2.0
Secure Doors 6684 3344 50% 0.00 3249 2988 92% 1.7
Self-Similar Strings 2093 1134 54% 0.02 288 257 89% 3.3
Selling Spatulas 2186 260 12% 0.01 285 164 58% 8.0
Sierpiński Circumference 3189 1205 38% 0.00 1060 942 89% 2.7
Sneak Attack 518 46 9% 0.00 51 23 45% 8.6
Sort of Sorting 16558 7297 44% 0.01 5441 4839 89% 2.0
Sort Two Numbers 8985 4845 54% 0.00 4668 4468 96% 1.4
Statistics 12435 5419 44% 0.00 5087 4678 92% 2.0
Stirling's Approximation 1114 449 40% 0.00 270 223 83% 4.7
Structural Differences 68 17 25% 0.01 24 13 54% 7.5
Substring Switcheroo 826 240 29% 0.26 205 163 80% 5.8
Sudokunique 1411 214 15% 0.01 188 79 42% 8.7
Support Vector Machine 1100 288 26% 0.02 286 204 71% 4.5
Surveillance Squared 217 49 23% 0.02 61 42 69% 5.7
Synchronizing Lists 6691 4085 61% 0.00 3596 3402 95% 1.6
Texture Analysis 3485 1479 42% 0.00 1372 1179 86% 2.7
The Rectangles Are Surrounding Us! 859 457 53% 0.00 405 347 86% 3.0
Transportation Planning 377 140 37% 0.05 122 105 86% 4.8
Unicycle Counting 241 55 23% 0.00 77 49 64% 7.0
Variable Arithmetic 1582 702 44% 0.00 679 611 90% 2.5
Volume Amplification 416 133 32% 0.11 100 65 65% 6.7
Where to Live? 829 314 38% 0.00 280 232 83% 4.0
Zipline 3491 1262 36% 0.00 961 797 83% 3.2