1936-AddMinimumNumberOfRungs.go

package main

// 1936. Add Minimum Number of Rungs
// You are given a strictly increasing integer array rungs that represents the height of rungs on a ladder. 
// You are currently on the floor at height 0, and you want to reach the last rung.

// You are also given an integer dist. 
// You can only climb to the next highest rung if the distance between where you are currently at (the floor or on a rung) and the next rung is at most dist. 
// You are able to insert rungs at any positive integer height if a rung is not already there.

// Return the minimum number of rungs that must be added to the ladder in order for you to climb to the last rung.

// Example 1:
// Input: rungs = [1,3,5,10], dist = 2
// Output: 2
// Explanation:
// You currently cannot reach the last rung.
// Add rungs at heights 7 and 8 to climb this ladder. 
// The ladder will now have rungs at [1,3,5,7,8,10].

// Example 2:
// Input: rungs = [3,6,8,10], dist = 3
// Output: 0
// Explanation:
// This ladder can be climbed without adding additional rungs.

// Example 3:
// Input: rungs = [3,4,6,7], dist = 2
// Output: 1
// Explanation:
// You currently cannot reach the first rung from the ground.
// Add a rung at height 1 to climb this ladder.
// The ladder will now have rungs at [1,3,4,6,7].

// Constraints:
//     1 <= rungs.length <= 10^5
//     1 <= rungs[i] <= 10^9
//     1 <= dist <= 10^9
//     rungs is strictly increasing.

import "fmt"

func addRungs(rungs []int, dist int) int {
    res := 0
    rungs = append([]int{0}, rungs...)
    for k := 0; k < len(rungs) - 1; k++ { //  // Iterate through the slice until the second to last element
        diff := rungs[k + 1] - rungs[k]
        if diff > dist { // if the difference between the next element and the current is greater than distance
            res += diff / dist // divide the difference by the steps and take the floor
            if diff % dist == 0 { // if the modulo is non-zero, subtract one from the added rungs
                res--
            }
        }
    }
    return res
}

func main() {
    // Example 1:
    // Input: rungs = [1,3,5,10], dist = 2
    // Output: 2
    // Explanation:
    // You currently cannot reach the last rung.
    // Add rungs at heights 7 and 8 to climb this ladder. 
    // The ladder will now have rungs at [1,3,5,7,8,10].
    fmt.Println(addRungs([]int{1,3,5,10}, 2)) // 2
    // Example 2:
    // Input: rungs = [3,6,8,10], dist = 3
    // Output: 0
    // Explanation:
    // This ladder can be climbed without adding additional rungs.
    fmt.Println(addRungs([]int{3,6,8,10}, 3)) // 0
    // Example 3:
    // Input: rungs = [3,4,6,7], dist = 2
    // Output: 1
    // Explanation:
    // You currently cannot reach the first rung from the ground.
    // Add a rung at height 1 to climb this ladder.
    // The ladder will now have rungs at [1,3,4,6,7].
    fmt.Println(addRungs([]int{3,4,6,7}, 2)) // 1
}