[LeetCode] Minimum Index Sum of Two Lists 兩個表單的最小座標和
阿新 • • 發佈:2018-12-27
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.
這道題給了我們兩個字串陣列,讓我們找到座標位置之和最小的相同的字串。那麼對於這種陣列項和其座標之間關係的題,最先考慮到的就是要建立資料和其位置座標之間的對映。我們建立list1的值和座標的之間的對映,然後遍歷list2,如果當前遍歷到的字串在list1中也出現了,那麼我們計算兩個的座標之和,如果跟我們維護的最小座標和mn相同,那麼將這個字串加入結果res中,如果比mn小,那麼mn更新為這個較小值,然後將結果res清空並加入這個字串,參見程式碼如下:
class Solution { public: vector<string> findRestaurant(vector<string>& list1, vector<string>& list2) { vector<string> res; unordered_map<string, int> m; int mn = INT_MAX, n1 = list1.size(), n2 = list2.size(); for (int i = 0; i < n1; ++i) m[list1[i]] = i; for (int i = 0; i < n2; ++i) { if (m.count(list2[i])) { int sum = i + m[list2[i]]; if (sum == mn) res.push_back(list2[i]); else if (sum < mn) { mn = sum; res = {list2[i]}; } } } return res; } };
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