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Implemented 'Find the Array Concatenation Value' challenge
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LeetCode/LeetCode/Challenges/FindTheArrayConcatenationValue.swift
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| Original file line number | Diff line number | Diff line change |
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| @@ -0,0 +1,45 @@ | ||
| // | ||
| // FindTheArrayConcatenationValue.swift | ||
| // LeetCode | ||
| // | ||
| // Created by William Boles on 11/06/2024. | ||
| // | ||
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| import Foundation | ||
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| //https://leetcode.com/problems/find-the-array-concatenation-value/ | ||
| struct FindTheArrayConcatenationValue { | ||
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| //Time: O(n) where n is the number of elements in `nums` | ||
| //Space: O(1) | ||
| //array | ||
| //two pointers | ||
| //string | ||
| // | ||
| //Solution Description: | ||
| //Using two pointers we work out->in. We take the int values at each pointer and concatenate them into a string and then | ||
| //into a single int value which we then add to `result`. We repeat this process until `p1` crosses `p2`, if `p1` is equal | ||
| //to `p2` then it means that `nums` has an odd number of elements and we take that final element and add it `result`. | ||
| func findTheArrayConcVal(_ nums: [Int]) -> Int { | ||
| var result = 0 | ||
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| var p1 = 0 | ||
| var p2 = nums.count - 1 | ||
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| while p1 < p2 { | ||
| let strValue = "\(nums[p1])\(nums[p2])" | ||
| let intValue = Int(strValue)! | ||
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| result += intValue | ||
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| p1 += 1 | ||
| p2 -= 1 | ||
| } | ||
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| if p1 == p2 { | ||
| result += nums[p1] | ||
| } | ||
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| return result | ||
| } | ||
| } |
31 changes: 31 additions & 0 deletions
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LeetCode/LeetCodeTests/Tests/FindTheArrayConcatenationValueTests.swift
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,31 @@ | ||
| // | ||
| // FindTheArrayConcatenationValueTests.swift | ||
| // LeetCodeTests | ||
| // | ||
| // Created by William Boles on 11/06/2024. | ||
| // | ||
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| import XCTest | ||
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| @testable import LeetCode | ||
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| final class FindTheArrayConcatenationValueTests: XCTestCase { | ||
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| // MARK: - Tests | ||
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| func test_A() { | ||
| let nums = [7,52,2,4] | ||
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| let result = FindTheArrayConcatenationValue().findTheArrayConcVal(nums) | ||
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| XCTAssertEqual(result, 596) | ||
| } | ||
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| func test_B() { | ||
| let nums = [5,14,13,8,12] | ||
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| let result = FindTheArrayConcatenationValue().findTheArrayConcVal(nums) | ||
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| XCTAssertEqual(result, 673) | ||
| } | ||
| } |