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| Dec 1, 2011 | » | [ToDo] CS 97SI: Introduction to Programming Contests
1 min; updated Sep 5, 2022
Introduction Mathematics Data Structures Dynamic Programming (DP) Combinatorial Games Basic Graph Algorithms Shortest Path Algorithms Network Flow Problems Computational Geometry String Algorithms Suffix Arrays CS 97SI: Introduction to Programming Contests. Jaehyun Park. stanford.edu . 2011. |
| Jun 20, 2020 | » | 01. Sum of Powers
2 min; updated Jun 20, 2020
The sums of powers, \( \sum_{k=1}^{n} k^a \), can be computed more efficiently if we have a closed formula for them. Sum of powers for a = 1, 2, 3 $$ \sum_{k=1}^{n} k = \frac{n(n+1)}{2} $$ One [intuitive] derivation is presented at brilliant.org : $$ S_n = 1 + 2 + 3 + … + n $$ … can be reordered as: $$ S_n = n + (n-1) + (n-2) + … + 1 $$... |