Problems by Greg Hamerly

Submissions Users
Name   Total Acc. Ratio Fastest Total Acc. Ratio Difficulty
Adding Words 14249 3526 25% 0.00 3301 2588 78% 3.8
Add Two Numbers 2000 1474 74% 0.00 1407 1369 97% 1.2
All Different Directions 1686 782 46% 0.00 743 664 89% 2.5
Bag of Tiles 855 274 32% 0.10 208 158 76% 6.2
BASIC Interpreter 1884 369 20% 0.01 322 221 69% 6.2
Birthday Paradox 232 87 38% 0.00 80 69 86% 4.4
Bounding Robots 2742 1609 59% 0.00 1524 1448 95% 1.6
Cellular Merging 87 11 13% 0.01 12 5 42% 8.0
Charting Progress 2924 1301 44% 0.00 1122 1027 92% 2.1
Chatter 285 138 48% 0.15 89 81 91% 4.2
Checking For Correctness 1812 539 30% 0.01 466 379 81% 4.1
Connect the Dots 1125 421 37% 0.00 385 331 86% 3.8
Convex Polygon Area 1674 1054 63% 0.00 939 894 95% 1.8
Counting Stars 8279 2735 33% 0.00 2221 1916 86% 2.8
Dart Scoring 587 220 37% 0.00 189 156 83% 4.5
Das Blinkenlights 5813 2673 46% 0.00 2286 2143 94% 1.7
Deduplicating Files 3640 1092 30% 0.01 973 743 76% 4.4
Detailed Differences 12133 6421 53% 0.00 5796 5593 96% 1.4
Different Distances 5051 2552 51% 0.00 2365 2224 94% 1.6
Echo Echo Echo 1308 1021 78% 0.00 957 947 99% 1.2
Engineering English 5406 2546 47% 0.00 2359 2039 86% 2.0
Enlarging Hash Tables 2794 917 33% 0.00 708 601 85% 3.1
Erdős Numbers 911 283 31% 0.01 244 191 78% 4.7
Escape Plan 699 210 30% 0.01 191 143 75% 5.7
Estimating the Area of a Circle 4859 3052 63% 0.00 2924 2784 95% 1.4
Forest Fires 176 73 41% 0.18 61 51 84% 4.5
Functional Fun 1584 724 46% 0.00 625 591 95% 1.9
Fundamental Neighbors 1017 427 42% 0.00 354 284 80% 4.4
Generalized Recursive Functions 625 252 40% 0.02 196 166 85% 4.2
Genetic Search 1065 593 56% 0.00 501 461 92% 2.1
Gerrymandering 2852 1848 65% 0.00 1685 1622 96% 1.5
Golomb Rulers 981 514 52% 0.02 458 408 89% 3.1
Hall O' Wee Mirrors 197 89 45% 0.00 82 67 82% 4.8
Heliocentric 2647 1541 58% 0.00 1372 1289 94% 1.8
Hitting the Targets 2294 1336 58% 0.00 1294 1208 93% 1.6
How Many Digits? 6835 1940 28% 0.00 1623 1284 79% 3.6
Hurricane Danger! 779 220 28% 0.00 245 177 72% 5.3
Image Decoding 1865 532 29% 0.00 547 449 82% 3.2
Island Hopping 2342 1170 50% 0.02 825 735 89% 2.9
Juggling Patterns 574 162 28% 0.00 136 101 74% 5.6
Limited Correspondence 938 201 21% 0.03 117 74 63% 7.2
Loopy Cab Drivers 417 110 26% 0.01 85 76 89% 5.4
Loopy Transit 207 121 58% 0.00 118 104 88% 3.1
Managing Packaging 690 243 35% 0.01 225 145 64% 5.8
Mandelbrot 3116 966 31% 0.00 861 756 88% 2.9
Matrix Inverse 3277 1185 36% 0.00 1153 983 85% 2.8
Maximizing (And Minimizing) Your Winnings 814 336 41% 0.07 259 218 84% 4.1
Maximizing Your Pay 415 129 31% 0.00 121 87 72% 6.5
Maze Movement 517 279 54% 0.06 226 195 86% 4.1
Metaprogramming 2980 1297 44% 0.00 1175 1050 89% 2.1
Missing Numbers 6161 3368 55% 0.00 3053 2867 94% 1.5
Multi-Touch Gesture Classification 115 28 24% 0.00 25 20 80% 6.5
Musical Notation 1193 605 51% 0.00 576 544 94% 1.9
Music Your Way 1463 754 52% 0.00 673 612 91% 2.3
Name That Permutation 735 293 40% 0.00 269 223 83% 4.6
Notable Quotables 88 13 15% 0.00 23 12 52% 7.0
Oddities 31959 17246 54% 0.00 15297 14703 96% 1.7
Out of Context 31 10 32% 0.04 12 7 58% 7.9
Pachinko Probability 399 153 38% 0.00 157 127 81% 5.8
Pachyderm Peanut Packing 733 504 69% 0.00 479 451 94% 1.9
Page Layout 772 210 27% 0.02 136 111 82% 5.5
Parallel Analysis 314 142 45% 0.08 107 93 87% 3.6
Parsing Hex 2584 811 31% 0.00 818 707 86% 2.7
Permutation Encryption 4340 1616 37% 0.00 1564 1364 87% 2.5
Polish Notation 1697 484 29% 0.00 392 321 82% 3.3
Preludes 2141 1150 54% 0.00 1122 1053 94% 1.8
Primal Representation 1856 559 30% 0.02 456 364 80% 4.9
Prime Reduction 3103 1091 35% 0.03 735 617 84% 3.7
Prime Spiral 645 272 42% 0.00 207 184 89% 3.4
Quick Estimates 11204 6320 56% 0.00 5902 5617 95% 1.4
Quite a Problem 4189 1788 43% 0.00 1675 1522 91% 2.1
Race Day 444 190 43% 0.00 159 133 84% 4.1
Reachable Roads 3321 1627 49% 0.00 1337 1218 91% 2.4
Reversing Roads 2520 581 23% 0.00 509 398 78% 4.6
Robot Protection 1414 612 43% 0.02 382 347 91% 2.6
Saving Daylight 2500 1362 54% 0.00 1306 1194 91% 2.1
Secure Doors 5900 2902 49% 0.00 2848 2605 91% 1.8
Self-Similar Strings 778 431 55% 0.02 252 223 88% 3.4
Selling Spatulas 1637 208 13% 0.01 226 126 56% 8.0
Sierpiński Circumference 3020 1146 38% 0.00 997 894 90% 2.5
Sneak Attack 484 42 9% 0.00 44 19 43% 8.9
Sort of Sorting 13601 5860 43% 0.01 4295 3791 88% 2.1
Sort Two Numbers 1109 727 66% 0.00 715 683 96% 1.4
Statistics 10818 4679 43% 0.00 4419 4069 92% 2.4
Stirling's Approximation 1043 414 40% 0.00 235 194 83% 4.8
Structural Differences 66 16 24% 0.01 22 12 55% 7.5
Substring Switcheroo 784 218 28% 0.26 189 149 79% 5.3
Sudokunique 1327 195 15% 0.01 175 72 41% 8.8
Support Vector Machine 1056 274 26% 0.02 274 193 70% 4.7
Surveillance Squared 177 40 23% 0.02 51 34 67% 7.1
Synchronizing Lists 5768 3539 61% 0.00 3092 2927 95% 1.5
Texture Analysis 2875 1245 43% 0.00 1144 989 86% 2.6
The Rectangles Are Surrounding Us! 596 315 53% 0.00 282 236 84% 3.5
Transportation Planning 305 105 34% 0.05 90 81 90% 4.9
Unicycle Counting 193 45 23% 0.00 59 40 68% 7.3
Variable Arithmetic 1402 603 43% 0.00 595 531 89% 2.6
Volume Amplification 367 124 34% 0.11 89 57 64% 7.2
Where to Live? 751 290 39% 0.01 250 209 84% 4.0
Zipline 3221 1123 35% 0.00 868 713 82% 3.2