1184. Distance Between Bus Stops

1184. Distance Between Bus Stops (Easy)

A bus has n stops numbered from 0 to n - 1 that form a circle. We know the distance between all pairs of neighboring stops where distance[i] is the distance between the stops number i and (i + 1) % n.

The bus goes along both directions i.e. clockwise and counterclockwise.

Return the shortest distance between the given start and destination stops.

 

Example 1:

Input: distance = [1,2,3,4], start = 0, destination = 1
Output: 1
Explanation: Distance between 0 and 1 is 1 or 9, minimum is 1.

 

Example 2:

Input: distance = [1,2,3,4], start = 0, destination = 2
Output: 3
Explanation: Distance between 0 and 2 is 3 or 7, minimum is 3.

 

Example 3:

Input: distance = [1,2,3,4], start = 0, destination = 3
Output: 4
Explanation: Distance between 0 and 3 is 6 or 4, minimum is 4.

 

Constraints:

• 1 <= n <= 10^4
• distance.length == n
• 0 <= start, destination < n
• 0 <= distance[i] <= 10^4

Companies:
Google

Related Topics:
Array

Solution 1.

// OJ: https://leetcode.com/problems/distance-between-bus-stops/
// Author: github.com/lzl124631x
// Time: O(N)
// Space: O(1)
class Solution {
public:
    int distanceBetweenBusStops(vector<int>& distance, int start, int destination) {
        if (start == destination) return 0;
        if (start > destination) swap(start, destination);
        int sum = 0, path = 0, N = distance.size();
        for (int i = 0; i < N; ++i) {
            if (i >= start & i < destination) path += distance[i];
            sum += distance[i];
        }
        return min(path, sum - path);
    }
};