# Contests

I contribute to the National Olympiad in Informatics – Philippines. I help write and test problems, and help train the Philippine team to the IOI. I talk more about this in Helping out in our NOI.

Back when we didn’t have dedicated artists, I made art for some problems. Here’s the header for Sorting the Planets:

## Problems

Here are my problems used for public NOI.PH rounds:

### Tulkinao

From NOI.PH 2023 Finals. A string combinatorics problem.

### Makafeeling Ka

From NOI.PH 2023 Finals. An interactive substring query problem.

### Ang Talon ni Maria Cristina

From NOI.PH 2023 Finals. An ad hoc array modification problem.

### Pre-In-Post

From NOI.PH 2023 Eliminations. A combinatorics problem.

### Abakoda Round 3

From Abakoda 2021. A round of four math problems.

### Psari-Psari

From NOI.PH 2021 Finals. An ad hoc problem.

### Functional Alchemy

From NOI.PH 2020 Finals. An ad hoc problem.

### Partial Reduplication

From NOI.PH 2020 Eliminations. A simple string processing problem.

### Pakain ng Pahiyas 2

From NOI.PH 2020 Eliminations. A math problem that involves some counting.

### Sorting the Planets

From NOI.PH 2019 Finals. A challenging ad hoc problem that can be solved mostly through clever observations.

### Exchange Gift

From NOI.PH 2019 Eliminations. A data structure problem about careful implementation.

## Reflections

After writing reflections for math contests, I decided to write reflections for programming contests I joined as well. These cover my junior and senior years in high school:

2017 | NOI.PH Finals Reflections |

NOI.PH Team Round Reflections | |

2018 | DISCS PRO Reflections |

NOI.PH Finals Reflections | |

IOI Reflections |