Problems by Greg Hamerly

Submissions Users
Name   Total Acc. Ratio Fastest Total Acc. Ratio Difficulty
Adding Words 14915 3664 25% 0.00 3432 2687 78% 3.9
Add Two Numbers 5684 3775 66% 0.00 3551 3417 96% 1.3
All Different Directions 1747 810 46% 0.00 768 687 89% 2.5
Bag of Tiles 922 300 33% 0.08 227 177 78% 6.0
BASIC Interpreter 1938 386 20% 0.01 336 232 69% 6.2
Birthday Paradox 234 88 38% 0.00 82 70 85% 5.2
Bounding Robots 2800 1645 59% 0.00 1560 1484 95% 1.6
Cellular Merging 87 11 13% 0.01 12 5 42% 8.1
Charting Progress 2991 1340 45% 0.00 1150 1054 92% 2.2
Chatter 306 151 49% 0.15 94 85 90% 4.1
Checking For Correctness 1861 556 30% 0.01 482 391 81% 4.2
Connect the Dots 1184 442 37% 0.00 407 350 86% 3.9
Convex Polygon Area 1732 1092 63% 0.00 970 921 95% 1.9
Counting Stars 11924 3410 29% 0.00 2607 2197 84% 4.0
Dart Scoring 592 222 38% 0.00 191 158 83% 4.5
Das Blinkenlights 6052 2778 46% 0.00 2381 2230 94% 1.7
Deduplicating Files 3776 1136 30% 0.01 1020 780 76% 4.3
Detailed Differences 12763 6728 53% 0.00 6071 5852 96% 1.4
Different Distances 5148 2620 51% 0.00 2424 2281 94% 1.6
Echo Echo Echo 5405 3551 66% 0.00 3244 3131 97% 1.3
Engineering English 5802 2646 46% 0.00 2463 2132 87% 2.1
Enlarging Hash Tables 2830 932 33% 0.00 720 611 85% 3.3
Erdős Numbers 945 291 31% 0.01 256 198 77% 4.8
Escape Plan 818 246 30% 0.01 211 158 75% 5.6
Estimating the Area of a Circle 5236 3236 62% 0.00 3097 2947 95% 1.5
Forest Fires 178 75 42% 0.18 63 53 84% 4.5
Functional Fun 1612 740 46% 0.00 640 605 95% 1.9
Fundamental Neighbors 1131 442 39% 0.00 368 296 80% 4.5
Generalized Recursive Functions 651 268 41% 0.02 206 175 85% 4.3
Genetic Search 1137 625 55% 0.00 533 489 92% 2.2
Gerrymandering 2940 1905 65% 0.00 1722 1655 96% 1.6
Golomb Rulers 1056 539 51% 0.02 476 426 89% 3.1
Hall O' Wee Mirrors 214 90 42% 0.00 89 68 76% 5.9
Heliocentric 2711 1572 58% 0.00 1397 1313 94% 1.8
Hitting the Targets 2360 1393 59% 0.00 1347 1261 94% 1.6
How Many Digits? 6881 1961 28% 0.00 1642 1300 79% 3.7
Hurricane Danger! 807 227 28% 0.00 249 181 73% 5.4
Image Decoding 1989 567 29% 0.00 576 471 82% 3.3
Island Hopping 2480 1228 50% 0.02 874 780 89% 3.0
Juggling Patterns 603 172 29% 0.00 146 109 75% 5.9
Limited Correspondence 942 202 21% 0.03 118 75 64% 7.4
Loopy Cab Drivers 424 112 26% 0.01 89 78 88% 6.2
Loopy Transit 221 125 57% 0.00 127 108 85% 4.3
Managing Packaging 724 251 35% 0.01 232 151 65% 5.8
Mandelbrot 3220 992 31% 0.00 898 782 87% 3.2
Matrix Inverse 3380 1226 36% 0.00 1201 1019 85% 2.9
Maximizing (And Minimizing) Your Winnings 828 344 42% 0.07 265 224 85% 4.2
Maximizing Your Pay 453 142 31% 0.00 127 92 72% 6.4
Maze Movement 557 290 52% 0.06 234 202 86% 4.2
Metaprogramming 3088 1351 44% 0.00 1221 1092 89% 2.2
Missing Numbers 6680 3628 54% 0.00 3281 3076 94% 1.6
Multi-Touch Gesture Classification 118 29 25% 0.00 26 21 81% 6.5
Musical Notation 1230 624 51% 0.00 594 561 94% 2.0
Music Your Way 1539 793 52% 0.00 709 647 91% 2.2
Name That Permutation 758 304 40% 0.00 278 232 83% 4.6
Notable Quotables 92 15 16% 0.00 25 14 56% 7.0
Oddities 33261 18013 54% 0.00 15891 15272 96% 1.5
Out of Context 31 10 32% 0.04 12 7 58% 7.9
Pachinko Probability 407 157 39% 0.00 161 131 81% 5.9
Pachyderm Peanut Packing 802 544 68% 0.00 502 474 94% 1.9
Page Layout 786 219 28% 0.02 142 117 82% 5.4
Parallel Analysis 324 144 44% 0.08 109 95 87% 3.8
Parsing Hex 2737 851 31% 0.00 859 743 86% 2.7
Permutation Encryption 4491 1667 37% 0.00 1612 1406 87% 2.6
Polish Notation 1729 495 29% 0.00 403 331 82% 3.3
Preludes 2243 1197 53% 0.00 1163 1091 94% 1.9
Primal Representation 1888 573 30% 0.02 463 372 80% 4.9
Prime Reduction 3133 1104 35% 0.03 745 626 84% 3.8
Prime Spiral 657 280 43% 0.00 211 188 89% 3.4
Quick Estimates 11898 6657 56% 0.00 6223 5919 95% 1.5
Quite a Problem 4366 1846 42% 0.00 1736 1574 91% 2.2
Race Day 448 193 43% 0.00 162 136 84% 4.2
Reachable Roads 3500 1715 49% 0.00 1389 1265 91% 2.5
Reversing Roads 2554 590 23% 0.00 517 404 78% 4.7
Robot Protection 1453 635 44% 0.02 394 359 91% 2.7
Saving Daylight 2611 1417 54% 0.00 1351 1234 91% 2.1
Secure Doors 6103 3027 50% 0.00 2963 2717 92% 1.7
Self-Similar Strings 1163 643 55% 0.02 263 234 89% 3.4
Selling Spatulas 1738 221 13% 0.01 242 135 56% 8.1
Sierpiński Circumference 3039 1158 38% 0.00 1008 904 90% 2.6
Sneak Attack 485 42 9% 0.00 45 19 42% 9.0
Sort of Sorting 14451 6242 43% 0.01 4613 4078 88% 2.2
Sort Two Numbers 4594 2634 57% 0.00 2547 2433 96% 1.4
Statistics 11149 4842 43% 0.00 4576 4214 92% 2.3
Stirling's Approximation 1079 431 40% 0.00 249 205 82% 4.8
Structural Differences 66 16 24% 0.01 22 12 55% 7.6
Substring Switcheroo 809 233 29% 0.26 196 156 80% 5.5
Sudokunique 1337 201 15% 0.01 178 73 41% 8.8
Support Vector Machine 1069 282 26% 0.02 280 199 71% 4.7
Surveillance Squared 202 45 22% 0.02 56 39 70% 6.3
Synchronizing Lists 5984 3668 61% 0.00 3212 3042 95% 1.5
Texture Analysis 3012 1293 43% 0.00 1188 1021 86% 2.7
The Rectangles Are Surrounding Us! 635 331 52% 0.00 295 249 84% 3.5
Transportation Planning 318 114 36% 0.05 97 88 91% 4.8
Unicycle Counting 197 48 24% 0.00 61 42 69% 7.2
Variable Arithmetic 1452 622 43% 0.00 611 548 90% 2.6
Volume Amplification 367 124 34% 0.11 89 57 64% 7.3
Where to Live? 761 296 39% 0.00 257 215 84% 4.1
Zipline 3303 1163 35% 0.00 888 729 82% 3.4