1184. Distance Between Bus Stops --------E

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

 

A:

一开始看错题意了。 以为是start < destination.  结果

• 0 <= start, destination < n

class Solution {
public:
    int distanceBetweenBusStops(vector<int>& distance, int start, int destination) {
        int n = distance.size();
        if(destination < start){
            int tmp = destination;
            destination = start;
            start = tmp;
        }
            
            
        int left = 0;
        for(int i = start; i<destination;i++){
            left += distance[i];
        }
        int right = 0;
        for(int i = destination; i< start+n; i++){
            int j = i%n;
            right += distance[j];
        }
        return min(left,right);
    }
};