Today I have done Distance Between Bus Stops and leetcode's June LeetCoding Challenge with cpp.

Distance Between Bus Stops

Description

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

Solution

class Solution {
public:
  int distanceBetweenBusStops(vector<int>& distance, int start, int destination) {
    int sum = 0;
    int d = 0;
    for(auto i : distance) sum += i;
    for(int i = min(start, destination); i < max(start, destination); ++i) {
      d += distance[i];
    }
    return min(d, sum - d);
  }
};

June LeetCoding Challenge 9

Description

Jump Game VI

You are given a 0-indexed integer array nums and an integer k.

You are initially standing at index 0. In one move, you can jump at most k steps forward without going outside the boundaries of the array. That is, you can jump from index i to any index in the range [i + 1, min(n - 1, i + k)] inclusive.

You want to reach the last index of the array (index n - 1). Your score is the sum of all nums[j] for each index j you visited in the array.

Return the maximum score you can get.

Example 1:

Input: nums = [1,-1,-2,4,-7,3], k = 2
Output: 7
Explanation: You can choose your jumps forming the subsequence [1,-1,4,3] (underlined above). The sum is 7.

Example 2:

Input: nums = [10,-5,-2,4,0,3], k = 3
Output: 17
Explanation: You can choose your jumps forming the subsequence [10,4,3] (underlined above). The sum is 17.

Example 3:

Input: nums = [1,-5,-20,4,-1,3,-6,-3], k = 2
Output: 0

Constraints:

• 1 <= nums.length, k <= 10^5
• -10^4 <= nums[i] <= 10^4

Solution

class Solution {
public:
  int maxResult(vector<int>& nums, int k) {
    priority_queue<pair<int, int>> pq;
    int len = nums.size();
    int answer = nums[0];
    pq.push({nums[0], 0});
    for(int i = 1; i < len; ++i) {
      while(pq.top().second + k < i) pq.pop();
      answer = pq.top().first + nums[i];
      pq.push({answer, i});
    }
    return answer;
  }
};