### Problem
Cities are numbered 1 through `n`, and each road is an undirected edge with a positive distance. A route from city 1 to city `n` may repeat roads and cities, including either endpoint. Its score is the smallest road distance used anywhere along that route. Return the minimum possible score. At least one route from 1 to `n` exists, though other cities may be disconnected.
```cpp
class Solution {
public:
int minScore(int n, vector<vector<int>>& roads);
};
```
### Examples
**Example 1:**
```text
Input: n = 3, roads = [[1,2,8],[2,3,7],[1,3,9]]
Output: 7
Explanation: Route 1-2-3 has score 7, the smallest road weight in that component.
```
**Example 2:**
```text
Input: n = 4, roads = [[1,4,10],[1,2,2]]
Output: 2
Explanation: Detour 1-2-1-4 includes the weight2 road; isolated city3 is irrelevant.
```
### Constraints
- `2 <= n <= 100000`; `1 <= roads.length <= 100000`.
- Each road has distinct endpoints in[1, n]and distance in[1,10000].
- No edge is repeated.
- Cities 1 and n are connected; other cities need not be.
### Clarifying Questions
- Is the score a sum of distances? No; it is the smallest distance of any road used.
- Can a route revisit a city or road? Yes.
- Must every city be connected? No; only cities 1 and n are guaranteed connected.
- Is a route required in the answer? No; return only its minimum possible score.
```hint Check the boundary
Compare a route’s sum, maximum road distance and minimum road distance before choosing an objective.
```
Overview: Minimize the smallest road distance used on a route between two cities, allowing repeated roads and cities.
Cities are numbered 1 through n, and each road is an undirected edge with a positive distance. A route from city 1 to city n may repeat roads and cities, including either endpoint. Its score is the smallest road distance used anywhere along that route. Return the minimum possible score. At least one route from 1 to n exists, though other cities may be disconnected.
class Solution {
public:
int minScore(int n, vector<vector<int>>& roads);
};
Examples
Example 1:
Input: n = 3, roads = [[1,2,8],[2,3,7],[1,3,9]]
Output: 7
Explanation: Route 1-2-3 has score 7, the smallest road weight in that component.
Example 2:
Input: n = 4, roads = [[1,4,10],[1,2,2]]
Output: 2
Explanation: Detour 1-2-1-4 includes the weight2 road; isolated city3 is irrelevant.
Constraints
2 <= n <= 100000
;
1 <= roads.length <= 100000
.
Each road has distinct endpoints in[1, n]and distance in[1,10000].
No edge is repeated.
Cities 1 and n are connected; other cities need not be.
Clarifying Questions Guidance
Is the score a sum of distances? No; it is the smallest distance of any road used.
Can a route revisit a city or road? Yes.
Must every city be connected? No; only cities 1 and n are guaranteed connected.
Is a route required in the answer? No; return only its minimum possible score.