# 599. Minimum Index Sum of Two Lists

Easy
Given two arrays of strings `list1` and `list2`, find the common strings with the least index sum.
A common string is a string that appeared in both `list1` and `list2`.
A common string with the least index sum is a common string such that if it appeared at `list1[i]` and `list2[j]` then `i + j` should be the minimum value among all the other common strings.
Return all the common strings with the least index sum. Return the answer in any order.
Example 1:
Input: list1 = ["Shogun","Tapioca Express","Burger King","KFC"], list2 = ["Piatti","The Grill at Torrey Pines","Hungry Hunter Steakhouse","Shogun"]
Output: ["Shogun"]
Explanation: The only common string is "Shogun".
Example 2:
Input: list1 = ["Shogun","Tapioca Express","Burger King","KFC"], list2 = ["KFC","Shogun","Burger King"]
Output: ["Shogun"]
Explanation: The common string with the least index sum is "Shogun" with index sum = (0 + 1) = 1.
Example 3:
Explanation: There are three common strings:
"happy" with index sum = (0 + 1) = 1.
"sad" with index sum = (1 + 0) = 1.
"good" with index sum = (2 + 2) = 4.
The strings with the least index sum are "sad" and "happy".
Constraints:
• `1 <= list1.length, list2.length <= 1000`
• `1 <= list1[i].length, list2[i].length <= 30`
• `list1[i]` and `list2[i]` consist of spaces `' '` and English letters.
• All the strings of `list1` are unique.
• All the strings of `list2` are unique.
• There is at least a common string between `list1` and `list2`.

### 解題

func findRestaurant(list1 []string, list2 []string) []string {
m := make(map[string]int)
for i, s := range list1 {
m[s] = i
}
arr := make([][]string, len(list1) + len(list2) + 1)
ans := 20000
for i, s := range list2 {
if v, ok := m[s]; ok {
arr[i + v] = append(arr[i + v], s)
ans = min(ans, i + v)
}
}
if ans == 20000 { return []string{} }
return arr[ans]
}
func min(a, b int) int {
if a < b { return a }
return b
}