Q

/ Helper functions:
chunk: { (where differ x) cut x }

	Problem	Solution
1	Rain Water	`rainWater: { sum abs x - (reverse maxs reverse x) & maxs x }`
2	MCO	1) `mco: { max sum each chunk x }` 2) `mco: { max { y * y + x } scan x }`
3	LCIS	1) `lcis: { 1 + max { y * y + x } scan (>) prior x }` 2) `lcis: { 1 + max sum each chunk 1 _ (>) prior x }`
4	Kadanes	`kadanes: { max { y \| y + x } scan x }`
5	SF2	`sf2: { 2 * max 1 _ (&) prior count each chunk x }` `sf2: { 2 * max (&) prior deltas (where differ x) , count x }`
6	Max Gap	`maxgap: { max 1 _ deltas asc x }`
7	Max Gap Count	`maxgapcount: { sum { x = max x } 1 _ deltas asc x }`
8	TCO	`tco: { 3 <= max sum each chunk x mod 2 }`
9	Skyline	`skyline: { count distinct maxs x }`
10	OceanView	`oceanview: { where reverse differ maxs reverse x }`

BQN, Uiua, APL & Kap

	Problem	BQN	Uiua	Kap	APL
1	Rain Water	+´(⌈`⌊⌈`⌾⌽)⊸-	`/+-∶↧⍜⇌\↥∶\↥..`	`+/⌈\«⌊»(⌈\⍢⌽)⍛-`	`⊢+.-⍨⌈\⌊(⌽⌈\∘⌽)`
2	MCO	1) ⌈´·+´¨(+`¬)⊸⊔ 2) ⌈´(⊢×+)`	1) `/↥⊜⧻.` 2) `/↥\(×+,)`	1) `⌈/≢¨⊂⍨` 2) `⌈/⊢«×»+\`	1) 🚫 2) `⌈/(≢¨⊆⍨)`
3	LCIS	1) {1+⌈´(⊢×+)`<´˘2↕𝕩} 2) 🚫	1)`+1/↥\(×+,)≡/>◫2` 2) `+1/↥⊜⧻.≡/≥◫2`	1) `1+⌈/⊢«×»+\2</` 2) `1+⌈/≢¨⊂⍨2</`	1) 🚫 2) `{1+⌈/≢¨⊆⍨2</⍵}`
4	Kadanes	⌈´(⊢⌈+)`	`/↥\(↥+,)`	`⌈/⊢«⌈»+\`	🚫
5	SF2	{2×⌈´⌊_p≠¨𝕩⊔˜0∾+`≠_p𝕩}	`×2/↥/↧◫2⊜⧻.`	`⌈/2⌊/≢¨⊆⍨1,2≠/`	`{2×⌈/2⌊/≢¨⍵⊂⍨1,2≠/⍵}`
6	Max Gap	`⌈´·-´˘2↕∨`	`/↥≡/-◫2⊏⌂.`	`⌈/2-/∨`	`{⌈/2-/(⊂⍤⍒⌷⊢)⍵}`
7	Max Gap Count	`+´·⌈´⊸=·-´˘2↕∨`	`/+=/↥.≡/-◫2⊏⌂.`	`+/⌈/⍛=2-/∨`	`{+/(⌈/=⊢)2-/(⊂⍤⍒⌷⊢)⍵}`
8	TCO	1)`{∨´∧´˘3↕2\|𝕩}` 2) {3≤⌈´(⊢×+)`2\|𝕩} 3) 🚫	1) `/↥≡/↧◫3◿2` 2) `≥3/↥\(×+,)◿2` 3) `≥3/↥⊜⧻.◿2`	1) `∨/3∧/2\|` 2) `3≤⌈/⊢«×»+\2\|` 3) `3≤⌈/≢¨⊂⍨2\|`	1) `∨/3∧/2\|⊢` 2) 🚫 3) `{3≤⌈/≢¨⊆⍨2\|⍵}`
9	Skyline	≠·⍷⌈`	`⧻⊝\↥`	`≢∪⌈\`	`{≢∪⌈\⍵}`
10	OceanView	1) 🚫 2) /0=(⊒⌈`)⌾⌽ 3) /⌈`⌾⌽⊸=	1) 🚫 2) 🚫 3) `▽∶⇡⧻∶=⍜⇌\↥..`	1) 🚫 2) 🚫 3) `⍸⌈\⍢⌽⍛=`	1) `{¯1+⍸⌽≠⌈\⌽⍵}` 2) 🚫 3) `{¯1+⍸⍵=⌽⌈\⌽⍵}`

In BQN, _p ← {𝔽´˘2↕𝕩}

	Problem	Jello	Jelly
1	Rain Water	`rev maxs rev min maxs _ . sum`	`ṚḾṚ«Ḿ_µS`
2	MCO	1) `part_len maxr` 2) `+ * r . scan maxr`	1) `ℙṀ` 2) `+×ṛµ\Ṁ`
3	LCIS	1) `< prior : + * r . scan maxr add1` 2) `< prior part_len maxr add1`	1) `<ṕð+×ṛµ\Ṁ‘` 2) `<ṕℙṀ‘`
4	Kadanes	`+ max r . scan maxr`	`+»ṛµ\Ṁ`
5	SF2	`group_len min prior maxr * 2`	`Œɠ«ṕṀ×2`
6	Max Gap	`sort deltas maxr`	`ṢIṀ`
7	Max Gap Count	`sort deltas idx_max len`	`ṢIML`
8	TCO	1) `odd? min 3 slide_fold any` 2) `odd? : + * r . scan maxr > 2` 3) `odd? part_len maxr > 2`	1) `Ḃ«3\Ẹ` 2) `Ḃð+×ṛµ\Ṁ>2` 3) `ḂℙṀ>2`
9	Skyline	`maxs uniq len`	`ḾQL`
10	OceanView	1) `rev maxs uniq_mask rev idx sub1` 2) 🚫 3) `rev maxs rev = . idx sub1`	1) `ṚḾŒQṚT’` 2) 🚫 3) `ṚḾṚ=µT’`