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⚡ Bolt: [O(N^2) Loop Optimization in Search Paging Pagination] #19

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⚡ Bolt: [O(N^2) Loop Optimization in Search Paging Pagination] #19

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7a028ee
Optimize O(N^2) list search in search pagination
LeanBitLab Oct 6, 2026
2efd26e
Optimize O(N^2) list search in search pagination
LeanBitLab Oct 6, 2026
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3 changes: 3 additions & 0 deletions .jules/bolt.md
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Expand Up @@ -3,3 +3,6 @@
## 2024-05-24 - O(N) Iteration in Cache Size Calculation
**Learning:** Calculating dynamic capacity dynamically via `store.values.sumOf { it.sizeBytes }` effectively incurs an O(N) cost on every `put` because it runs when `trimToCapacity()` calls `dynamicCapacity`. When cache sizes get large, this causes O(N²) overall insertion performance and UI stutters.
**Action:** Use an `AtomicLong` (O(1)) to track the running sum of cache size instead of dynamically iterating through the entire collection.
## 2024-10-06 - O(N^2) Lookup Optimization in List
**Learning:** Using `List.none { it.id == post.id }` within a loop creates an O(N^2) complexity because `none` iterates over the list which grows linearly.
**Action:** Replace `List.none` or `List.contains` checks on growing collections with an O(1) `Set.add` tracking mechanism when maintaining uniqueness.
4 changes: 3 additions & 1 deletion app/src/main/java/com/example/reddittube/data/DataRepository.kt
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Expand Up @@ -259,6 +259,7 @@ class DefaultDataRepository(private val context: Context) : DataRepository {
val token = RedditOAuthHelper.getOrFetchAccessToken(context)
if (token == null) { emit(SearchVideosResult(emptyList(), null)); return@flow }
val results = mutableListOf<RedditPost>()
val seenIds = mutableSetOf<String>()
var currentAfter = after
var finalAfter: String? = null
try {
Expand All @@ -276,7 +277,8 @@ class DefaultDataRepository(private val context: Context) : DataRepository {
for (i in 0 until children.length()) {
val childData = children.getJSONObject(i).optJSONObject("data") ?: continue
parseRedditPost(childData)?.let { post ->
if (results.none { it.id == post.id }) {
// Performance optimization: Avoid O(N^2) list search by using a Set for seen IDs
if (seenIds.add(post.id)) {
results.add(post)
}
}
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1 change: 0 additions & 1 deletion app/src/main/java/com/example/reddittube/ui/main/components/MinimalButton.kt
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Expand Up @@ -16,7 +16,6 @@ import androidx.compose.ui.draw.clip
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.semantics.Role
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.semantics.Role
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

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