[Swift]LeetCode599.两个列表的最小索引总和|MinimumIndexSumofTwoLists

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Suppose Andy and Doris want to choose a restaurant for dinner, and they both have a list of favorite restaurants represented by strings.

You need to help them find out their common interest with the least list index sum. If there is a choice tie between answers, output all of them with no order requirement. You could assume there always exists an answer.

Example 1:

Input:
["Shogun", "Tapioca Express", "Burger King", "KFC"]
["Piatti", "The Grill at Torrey Pines", "Hungry Hunter Steakhouse", "Shogun"]
Output: ["Shogun"]
Explanation: The only restaurant they both like is "Shogun".

Example 2:

Input:
["Shogun", "Tapioca Express", "Burger King", "KFC"]
["KFC", "Shogun", "Burger King"]
Output: ["Shogun"]
Explanation: The restaurant they both like and have the least index sum is "Shogun" with index sum 1 (0+1).

Note:

The length of both lists will be in the range of [1, 1000].
The length of strings in both lists will be in the range of [1, 30].
The index is starting from 0 to the list length minus 1.
No duplicates in both lists.

假设Andy和Doris想在晚餐时选择一家餐厅，并且他们都有一个表示最喜爱餐厅的列表，每个餐厅的名字用字符串表示。

你需要帮助他们用最少的索引和找出他们共同喜爱的餐厅。如果答案不止一个，则输出所有答案并且不考虑顺序。你可以假设总是存在一个答案。

示例 1:

输入:
["Shogun", "Tapioca Express", "Burger King", "KFC"]
["Piatti", "The Grill at Torrey Pines", "Hungry Hunter Steakhouse", "Shogun"]
输出: ["Shogun"]
解释: 他们唯一共同喜爱的餐厅是“Shogun”。

示例 2:

输入:
["Shogun", "Tapioca Express", "Burger King", "KFC"]
["KFC", "Shogun", "Burger King"]
输出: ["Shogun"]
解释: 他们共同喜爱且具有最小索引和的餐厅是“Shogun”，它有最小的索引和1(0+1)。

提示:

两个列表的长度范围都在 [1, 1000]内。
两个列表中的字符串的长度将在[1，30]的范围内。
下标从0开始，到列表的长度减1。
两个列表都没有重复的元素。

Runtime: 408 ms

Memory Usage: 20.4 MB

 1 class Solution {
 2     func findRestaurant(_ list1: [String], _ list2: [String]) -> [String] {
 3     var dict = [String: Int].init(minimumCapacity: list1.count)
 4     var dict1 = [String: Int].init(minimumCapacity: max(list1.count, list2.count))
 5     
 6     
 7     for (index,s) in list1.enumerated() {
 8         dict[s] = index
 9     }
10     var minIndex = list2.count + list1.count
11     for (index,s) in list2.enumerated() {
12         if let firstIndex = dict[s] {
13             let sum = firstIndex + index
14             minIndex = min(minIndex, sum)
15             dict1[s] = sum
16         }
17     }
18     var array = [String]()
19     for (key,value) in dict1 {
20         if value == minIndex {
21             array.append(key)
22         }
23     }
24     return array
25     }
26 }

476ms

 1 class Solution {
 2     func findRestaurant(_ list1: [String], _ list2: [String]) -> [String] {
 3         var mapping = [String: Int]()
 4         for i in 0..<list1.count {
 5             mapping[list1[i]] = i
 6         }
 7         
 8         var ret = [String]()
 9         var indexSum = Int.max
10         for j in 0..<list2.count {
11             if let i = mapping[list2[j]] {
12                 let s = i + j
13                 if s > indexSum { continue }
14                 if s < indexSum {
15                     indexSum = s
16                     ret.removeAll()
17                 }
18                 ret.append(list2[j])
19             }
20         }
21         return ret
22     }
23 }

480ms

 1 class Solution {
 2     func findRestaurant(_ list1: [String], _ list2: [String]) -> [String] {
 3         var difference = Int.max
 4         var result = [String]()
 5         var dict1 = [String: Int]()
 6         for i in 0..<list1.count {
 7             dict1[list1[i]] = i
 8         }
 9         for i in 0..<list2.count {
10             if let j = dict1[list2[i]] {
11                 if i+j < difference {
12                     difference = i+j
13                     result = [list1[j]]
14                 } else if i+j == difference {
15                     result += [list1[j]]
16                 }
17             }
18         }
19         return result
20     }
21 }

504ms

 1 class Solution {
 2     func findRestaurant(_ list1: [String], _ list2: [String]) -> [String] {
 3         var dict = [String: Int]()
 4         var bucket = [[String]](repeating: [String](), count: list1.count + list2.count)
 5         for (idx, rest) in list1.enumerated() {
 6             dict[rest] = (dict[rest] ?? 0) + idx
 7         }
 8         for (idx, rest) in list2.enumerated() {
 9             if let s = dict[rest] {
10                 bucket[s+idx].append(rest)
11             }
12         }
13         for b in bucket {
14             if !b.isEmpty {
15                 return b
16             }
17         }
18         return [String]()
19     }
20 }

512ms

 1 class Solution {
 2     func findRestaurant(_ list1: [String], _ list2: [String]) -> [String] {
 3         let A = list1.count
 4         let B = list2.count
 5         guard A > 0, B > 0 else{return []}
 6         var maxSum = A+B
 7         var hash = [String:Int]()
 8         var resultSet = Set<String>()
 9         for i in 0..<A{
10             hash[list1[i]] = i
11         }
12         
13         for i in 0..<B{
14             if hash[list2[i]] != nil{
15                 let sum = hash[list2[i]]! + i
16                 if sum < maxSum{
17                     resultSet.removeAll()
18                     resultSet.insert(list2[i])
19                     maxSum = sum
20                 }else if maxSum == sum{
21                     resultSet.insert(list2[i])
22                 }
23             }
24         }
25         
26         return Array(resultSet)
27     }
28 }

520ms

 1 class Solution {
 2     func findRestaurant(_ list1: [String], _ list2: [String]) -> [String] {
 3         let set1 = Set<String>(list1)
 4         let set2 = Set<String>(list2)
 5         let dst = set1.intersection(set2)
 6 
 7         var map1 = [String: Int]()
 8         for i in 0..<list1.count {
 9             if dst.contains(list1[i]) {
10                 map1[list1[i]] = i
11             }
12         }
13 
14         var map2 = [String: Int]()
15         for i in 0..<list2.count {
16             if dst.contains(list2[i]) {
17                 map2[list2[i]] = i
18             }
19         }
20 
21         var ans = [String]()
22         var minIndex = Int.max
23         dst.forEach { (c) in
24             let curIndex = map1[c]! + map2[c]!
25             if curIndex < minIndex {
26                 minIndex = curIndex
27             }
28         }
29 
30         dst.forEach { (c) in
31             let curIndex = map1[c]! + map2[c]!
32             if curIndex == minIndex {
33                 ans.append(c)
34             }
35         }
36 
37         return ans
38     }
39 }

556ms

 1 class Solution {
 2     func findRestaurant(_ list1: [String], _ list2: [String]) -> [String] {
 3     var dict = [String: Int].init(minimumCapacity: list1.count)
 4     var dict1 = [String: Int].init(minimumCapacity: max(list1.count, list2.count))
 5     
 6     
 7     for (index,s) in list1.enumerated() {
 8         dict[s] = index
 9     }
10     var minIndex = list2.count + list1.count
11     for (index,s) in list2.enumerated() {
12         if let firstIndex = dict[s] {
13             let sum = firstIndex + index
14             minIndex = min(minIndex, sum)
15             dict1[s] = sum
16         }
17     }
18     var array = [String]()
19     for (key,value) in dict1 {
20         if value == minIndex {
21             array.append(key)
22         }
23     }
24      return array
25     }
26 }

560ms

 1 class Solution {
 2     func findRestaurant(_ list1: [String], _ list2: [String]) -> [String] {
 3         var restMap: Dictionary<String, Int> = [:]
 4         for (index, rest) in list1.enumerated() {
 5             restMap[rest] = index
 6         }
 7 
 8         var minRest: [String] = []
 9         for (index, rest) in list2.enumerated() {
10             guard let currIndex = restMap[rest] else {
11                 continue
12             }
13             let listIndex = currIndex + index
14             let minListIndex = (minRest.count > 0) ? restMap[minRest[0]] ?? Int.max : Int.max
15             if listIndex == minListIndex {
16                 minRest.append(rest)
17             } else if listIndex < minListIndex {
18                 minRest = [rest]
19             }
20             restMap[rest] = listIndex
21         }
22 
23         return minRest
24     }
25 }

592ms

 1 class Solution {
 2     func findRestaurant(_ list1: [String], _ list2: [String]) -> [String] {
 3         var map1: [String: Int] = [:]
 4         for (i, s) in list1.enumerated() {
 5             map1[s] = i
 6         }
 7         
 8         var res: [String] = []
 9         var mn = Int.max
10         for (i, s) in list2.enumerated() {
11             if let value = map1[s] {
12                 if value + i < mn {
13                     res = [s]
14                     mn = value + i
15                 }
16                 else if value + i == mn {
17                     res.append(s)
18                 }
19             }
20         }
21         
22         return res
23     }
24 }

628ms

 1 class Solution {
 2     func findRestaurant(_ list1: [String], _ list2: [String]) -> [String] {
 3         var common = Set(list1).intersection(list2)
 4         let dic1 = Dictionary(uniqueKeysWithValues: zip(list1, 0..<list1.count))
 5         let dic2 = Dictionary(uniqueKeysWithValues: zip(list2, 0..<list2.count))
 6         var sum = Int.max
 7         var ans = [Int]()
 8         
 9         for rt in common {
10             let i = dic1[rt]!
11             let j = dic2[rt]!
12             if (i+j < sum) {
13                 ans = [i]
14                 sum = i+j
15             } else if (i+j == sum) {
16                 ans.append(i)
17             }
18         }
19         
20         return ans.compactMap{list1[$0]}
21     }
22 }

628ms

 1 class Solution {
 2     func findRestaurant(_ list1: [String], _ list2: [String]) -> [String] {
 3         guard list1.count > 0 && list2.count > 0 else {
 4             return []
 5         }
 6         
 7         var restaurantDict: [String: Int] = [:]
 8         var sumDict: [Int: [String]] = [:]
 9         
10         for (i, name) in list1.enumerated() {
11             restaurantDict[name] = i
12         }
13         
14         for (i, name) in list2.enumerated() {
15             if let sum = restaurantDict[name] {
16                 if sumDict[sum + i] != nil {
17                     sumDict[sum + i]!.append(name)
18                 } else {
19                     sumDict[sum + i] = [name]
20                 }
21             }
22         }
23         
24         let key = sumDict.keys.sorted().first ?? 0
25         
26         return sumDict[key] ?? []
27     }
28 }

19676 kb

 1 class Solution {
 2     func findRestaurant(_ list1: [String], _ list2: [String]) -> [String] {
 3         var result = [String]()
 4         var indexVal = Int.max
 5         
 6         for i in 0..<list1.count {
 7             for j in 0..<list2.count {
 8                 let indexOne = list1.index(list1.startIndex, offsetBy: i)
 9                 let indexTwo = list2.index(list2.startIndex, offsetBy: j)
10                 if list1[indexOne] == list2[indexTwo] {
11                     if (i + j) < indexVal {
12                         result = []
13                         indexVal = (i + j)
14                         result.append(list1[indexOne])
15                     }
16                     else if (i + j) == indexVal {
17                         result.append(list1[indexOne])
18                     }
19                 }
20             }
21         }
22         return result
23     }
24 }