While we strive to minimize the number of errors in the book, it is near impossible to have 0 error in a 681 pages Book 1+2 despite multiple re-reads by 20+ beta-readers.

Here is the list of known (minor) issues that are found **after** Sunday, 19 July 2020 initial release, ordered by severity, then by page numbers (tap the page number column if you view this page on a small screen for the full details).

Abbreviations used: S(everity: 3-extremely serious error/2-major error/1-minor grammatical or typographical error), B(ook 1 or 2), C(hapter 0/Preface, 1-9), P(age number), Pos(ition in the page), Ex(ercise), Fig(ure).

This list is last updated on Fri, 13 Jan 2023, ~3.51pm SGT.

Steven expects that this list should **not** grow that fast and will eventually 'stop' being updated anymore :).

However, if you spot any issue that is not already compiled below, please drop an email to Steven (stevenhalim at gmail dot com) with similar format as shown below.

P | S | B | C | Pos | The "Error" | The Fix |
---|---|---|---|---|---|---|

0-ix | 1 | 1 | 0-P | middle | "...of is teaching job..." | "...of his teaching job..." |

0-xxi | 1 | 1 | 0-P | middle | "...its basic form is much |
"...its basic form is much easier..." |

0-xix | 1 | 1 | 0-P | middle | The achievement info will always be out of date over time | See this instead |

15 | 1 | 1 | 1 | footnote 26 | Java is dropped after IOI 2020, Singapore (Online) | Focus on C++ and Python for CP in the 2020s |

17 | 1 | 1 | 1 | Ex 1.3.4.1, Q5 | There is a shorter Python answer | Add "Using C++, " |

20 | 2 | 1 | 1 | Ex 1.3.5.2, Q4+Q5 | 4 occurrences of \\n triggers 4 LaTeX new line commands | Ignore those 4 new lines |

27 | 2 | 1 | 1 | Take 1 | "...a > 1, b > 1, c > 1..." | "...a ≥ 1, b ≥ 1, c ≥ 1..." (as shown in the code) |

34 | 1 | 1 | 1 | Roman Numerals | "...uses |
"...uses certain letters..." |

41 | 1 | 1 | 1 | Ex 1.3.2.1 | Dragon of Loowater; Greedy ( |
Dragon of Loowater; Greedy (Classical) — this is classic in the 2020s |

42 | 2 | 1 | 1 | Task 4 | The tokens (integers) are sorted as strings | Add ", key=int" so that the tokens are sorted as integers |

42 | 2 | 1 | 1 | Task 6 | L[] = {10, 7, 5, 20, 8} is unsorted, but L is guaranteed to be sorted | sort it, i.e., L[] = {5, 7, 8, 10, 20} and remove the sort routine |

43 | 2 | 1 | 1 | Task 8 | printf("%d ", __builtin_ctz(ls)); | printf("%d ", __builtin_ctz(ls)+1); // 1-based output |

45 | 1 | 1 | 1 | Ex 1.3.5.2, task 2 | "...use __builtin_ctzl(v)..."; (1 'l' = unsigned long) |
"...use __builtin_ctzll(v)..."; (2 'l's = unsigned long long, safer) |

69 | 3 | 1 | 2 | Top+Bottom | Python list is not really a Linked List | Just use Python deque as queue to get O(1) popleft() |

82 | 2 | 1 | 2 | Bottom | "/month ([0.. |
Change it to "/month ([0..27/28/29/30])..." |

86 | 1 | 1 | 2 | Ex 2.3.3.2 | "...support |
"...support these..." |

87 | 1 | 1 | 2 | O(n^2) algorithm | "...is to this: find ..." | "...is to do this: find ..." |

105 | 1 | 1 | 2 | Top | "...the operation ((S) & (-S)) produces..." | "...the operation ((S) & -(S)) produces..." |

108 | 1 | 1 | 2 | Last line | "...we can |
"...we can slightly..." |

112 | 1 | 1 | 2 | Middle+Bottom | int v in range_update method in RUPQ and RURQ classes |
Change them to ll v to minimize overflow cases |

124 | 1 | 1 | 2 | Middle | Exercise 2.2.1. |
LaTeX referencing error, it should be Exercise 2.2.1.3* |

162 | 1 | 1 | 3 | Also p163 | Wrong usage of LaTeX itemize; '.' between playground and wordspin | Enumerate the list: a), b), ..., f); also use ',' between playground and wordspin |

168 | 1 | 1 | 3 | Bottom sample code | int dp(int g, b) { | int dp(int g, int b) { |

175 | 2 | 1 | 3 | Table 3.3 | cell A[1][3] on Table 3.3.B and C is not |
cell A[1][3] on Table 3.3.B and C should be -2 |

182 | 1 | 1 | 3 | Bottom | O(n!) Complete Search Algorithm | O(n!*n) Complete Search Algorithm |

184 | 1 | 1 | 3 | Ex 3.5.2.3* | "...the |
"...the minimum number of subsequences..." |

184 | 1 | 1 | 3 | Ex 3.5.2.3* | The second Exercise 3.5.2.3* is a LaTeX referencing error | It should be Exercise 3.5.2.4* |

213 | 2 | 1 | 4 | Kattis - hoppers | "...CC-1 if there is at least one bipartite component..." | "...CC-1 if there is at least one non-bipartite component..." |

223 | 2 | 1 | 4 | Middle | "...all edges have constant weight^{13} C" |
"...all edges have non-negative constant weight^{13} C" |

233 | 1 | 1 | 4 | Ex 4.4.3.5* | "...in O(V^2) instead such complete..." | "...in O(V^2) instead on such complete..." |

244 | 1 | 1 | 4 | Bottom | for (int |
for (int j = 0; j < V; ++j) |

245 | 1 | 1 | 4 | Top | printf(" %d", |
printf(" %d", j); |

260 | 2 | 1 | 4 | Ex 4.6.3.2* | "...randomize the vertex order in Adjacency List..." | "...randomize the vertex order in each row of the Adjacency List..." |

262 | 1 | 1 | 4 | Third line from the top | "...which we expand in ABCDA with AFGA." |
"...which we expand in ABCDA with AGFA." |

263 | 1 | 1 | 4 | Middle | "...involving it the last two decades..." | "...involving it in the last two decades..." |

263 | 2 | 1 | 4 | Middle | "does not have K_{5} or K_{3,3} as its subgraph" is not precise |
"does not contain a subgraph that is a subdivision of K_{5} or of K_{3,3}" |

267 | 2 | 1 | 4 | Ex 4.2.8.1 | The answer mentions 3 occurrences of "(directed)" | They should be "(undirected)" |

275 | 1 | 1 | 5 | Point 7 | "Note that r > 1" | "Note that r ≠ 1" |

285 | 1 | 1 | 5 | Marin Mersenne | "...was a French mathematician |
"...was a French mathematician" |

293 | 3 | 2 | 5 | Example 1+2+3 | 12 % 7 = |
12 % 7 = 5; also remove extra '(' in those 3 examples |

304 | 1 | 2 | 5 | The whole page | The section numbering: c, c, c, c is incorrect | It should be c, d, e, f |

312 | 1 | 2 | 5 | Middle | "...player id can subtract |
"...player id can subtract..." |

314 | 1 | 2 | 5 | Middle | "...problems that |
"...problems that are discussed..." |

315 | 2 | 2 | 5 | Middle | "Compute the number of |
"Compute the number of walks (repeated vertices are allowed) of length L" |

315 | 1 | 2 | 5 | Footnote 31 | "...elements of the matrix |
"...elements of the matrix are..." |

320 | 1 | 2 | 5 | Top | Incomplete constraint for Kattis - linearrecurrence | Add 1 ≤ N ≤ 40 as one of the constraints |

320 | 3 | 2 | 5 | Ex 5.8.4.2* | O(k^2 log n) is wrong | Change to O(k^3 log n) and lower k to k ≤ 100 |

322 | 2 | 2 | 5 | Ex 5.4.4.3 | "...%1e9+7 = ..." is missing parentheses | It should be "...%(1e9+7) = ..." |

322 | 2 | 2 | 5 | Ex 5.4.4.6 | "Let |
"Let B..."; ".., then |B| = 1M/7 = ..."; and "...|A ⋂ B| = 1M/35 = ..." |

323 | 3 | 2 | 5 | Ex 5.5.2 | The final answer is not 0.2 | It should be 7*6*5*4*3/(15*14*13*12*11) = 1/143 |

331 | 1 | 2 | 6 | Middle | "...what was the previous used..." | "...what was the previously used..." |

336 | 1 | 2 | 6 | Middle | "...the pattern can |
"...the pattern can be..." |

338 | 1 | 2 | 6 | Bottom | "We insertion of each..." | "We insert each..." |

345 | 2 | 2 | 6 | Middle | "Suffix 0 = 'GA |
"Suffix 0 = 'GATAGACA$'" |

356 | 2 | 2 | 6 | Top | "the S_{0,1,...,R} in the formulas have to be changed to T_{0,1,...,R} |
"the S_{0,1,...,R} in the formulas have to be changed to T_{0,1,...,R} |

356 | 1 | 2 | 6 | Bottom | "...we have take out..." | "...we have taken out..." |

365 | 1 | 2 | 7 | Middle | "...geometry-specific problems depend |
"...geometry-specific problems depend on..." |

374 | 1 | 2 | 7 | Top | The functions dot and norm_sq are already used 1 page earlier | They should have been declared in page 373 for angle function |

387 | 2 | 2 | 7 | Middle | "...where (P[i], P[i+1]) are consecutive |
"...where (P[i], P[i+1]) are consecutive vertices..." |

392 | 1 | 2 | 7 | Also page 391 | The implementation to find P0 actually finds the bottommost (and leftmost if tie) point |
Fortunately it is still correct |

393 | 1 | 2 | 7 | Middle | "But |
"But the convex hull must now be..." |

405 | 1 | 2 | 8 | Ex 8.2.1.2* | "...an arithmetic equation |
"...an arithmetic equation..." |

424 | 2 | 2 | 8 | Ex 8.2.1.2* | "...at Figure |
"...at Figure 8.16-3" and "...totalling 4+8 = 12..." |

429 | 1 | 2 | 8 | Top | "... pass it to our |
"... pass it to our Dinic's implementation..." |

414 | 1 | 2 | 8 | Code | "... a Boolean array 'used' ... calling rec(0, 0, 0) ... unordered_set 'used'" | "... a Boolean array 'visited' ... calling dp(0, 0, 0) ... unordered_set 'S'" |

416 | 1 | 2 | 8 | 8.3.6 | "... 200 * 2000 * 2000 = 8 * 10^6 initialization operations." |
"... 200 * 2000 * 2000 = 8 * 10^8 initialization operations." |

431 | 1 | 2 | 8 | Top | "Teams are |
"Teams are numbered..." |

431 | 1 | 2 | 8 | Ex 8.4.5.3* | "An potential..." | "A potential..." |

433 | 2 | 2 | 8 | Figure 8.22 | Missing dash at the bottom right corner | There should be a dash connecting '.' and '*' at the bottom right |

436 | 1 | 2 | 8 | Bottom | "...and later and Section..." | "...and later in Section..." |

436 | 1 | 2 | 8 | Footnote 16 | "...and each |
"...and each person..." |

438 | 2 | 2 | 8 | Middle | "...can be implemented in O(V^2). ... estimated to be O(V^2 + kE)." | "...can be implemented in O(V+E). ... estimated to be O(V+E + kE) = O(kE)." |

452 | 1 | 2 | 8 | Ex 8.6.6.2 | "...the input graph of the |
"...the input graph of the MVC..." |

452 | 1 | 2 | 8 | Ex 8.6.6.3* | "Does the Greedy algorithm work |
"Does the Greedy algorithm work..." |

453 | 3 | 2 | 8 | Fig 8.31, Left | MIS = |
MIS = {2, 4} |

459 | 2 | 2 | 8 | Fig 8.36 | "... These |
The middle K_{5} is not planar |

466 | 1 | 2 | 8 | Middle | "... illustration of Binary Search the Answer tecnique..." | "... illustration Binary Search the Answer technique" |

478 | 1 | 2 | 8 | Ex 8.4. |
LaTeX referencing error | It should be Exercise 8.4.4.1 |

481 | 2 | 2 | 9 | Last paragraph | "..., 1 |
"..., 15 rare problems." |

485 | 1 | 2 | 9 | Figure 9.1 | The second box has 2^4 = 4 | It should be 2^2 = 4 |

485 | 1 | 2 | 9 | Last line | "we want cover..." | "we want to cover..." |

497 | 2 | 2 | 9 | Bottom | "... a.mat[i][k] |
"... a.mat[i][k] * b.mat[k][j];" |

513 | 1 | 2 | 9 | Middle | "...of the |
"...of the same size as A[]..." |

526 | 1 | 2 | 9 | Middle | "...issue can be addressed by sub |
"...issue can be addressed by subtracting..." |

548 | 2 | 2 | 9 | Top | "...in Chapter 3+4 |
"...in Chapter 3+4+8 are 'uninformed'... |

549 | 2 | 2 | 9 | Top | "...visit the states in |
"...visit the states in non-decreasing order of... |

549 | 2 | 2 | 9 | Top | "...also known as admissible heuristic), this A* search algorithm is optimal... | Add a stronger constraint: consistent heuristic |

562 | 1 | 2 | 9 | Footnote 65 | "...A[i] > |
"...A[i] > |

563 | 1 | 2 | 9 | Footnote 66 | "..., work |
"..., work backwards, and..." |

564 | 1 | 2 | 9 | Middle | "...only i |
"...only iterates from..." |

571 | 1 | 2 | 9 | Middle | Missing "10 units of flow..." in the 3rd bullet point | Add "10 units of flow..." in the 3rd bullet point |