Floor and Ceil in Sorted Array in DSA Go - Build from Scratch

Floor and Ceil in Sorted Array

📖 Scenario: You are working with a sorted list of house numbers on a street. You want to find the closest house number that is less than or equal to a given number (floor) and the closest house number that is greater than or equal to that number (ceil).

🎯 Goal: Build a program that finds the floor and ceil values for a given number in a sorted array of house numbers.

📋 What You'll Learn

Create a sorted array of integers called houses with exact values

Create an integer variable called target for the number to find floor and ceil

Write a function findFloorAndCeil that takes houses and target and returns two integers: floor and ceil

Print the floor and ceil values in the format: Floor: X, Ceil: Y

💡 Why This Matters

🌍 Real World

Finding floor and ceil values is useful in real estate, pricing, and scheduling where you need closest matches in sorted data.

💼 Career

Understanding floor and ceil concepts helps in algorithm design, data querying, and optimization tasks common in software development.

1

Create the sorted array of house numbers

Create a sorted array of integers called houses with these exact values: 2, 5, 8, 12, 16, 23, 38, 56, 72, 91

DSA Go

# Create the sorted array houses with the exact values
# Your code here

Hint

Use houses := []int{2, 5, 8, 12, 16, 23, 38, 56, 72, 91} to create the array.

2

Set the target number to find floor and ceil

Create an integer variable called target and set it to 20

DSA Go

package main

func main() {
    houses := []int{2, 5, 8, 12, 16, 23, 38, 56, 72, 91}
    // Create target variable and set to 20
    // Your code here
}

Hint

Use target := 20 to create the variable.

3

Write the function to find floor and ceil

Write a function called findFloorAndCeil that takes houses []int and target int and returns two integers: floor and ceil. Use a simple loop to find the floor (largest number ≤ target) and ceil (smallest number ≥ target).

DSA Go

package main

func findFloorAndCeil(houses []int, target int) (int, int) {
    // Your code here
}

func main() {
    houses := []int{2, 5, 8, 12, 16, 23, 38, 56, 72, 91}
    target := 20
}

Hint

Loop through houses. Update floor if house ≤ target. Set ceil to first house ≥ target and break.

4

Print the floor and ceil values

Call findFloorAndCeil with houses and target. Print the floor and ceil values in the format: Floor: X, Ceil: Y

DSA Go

package main

func findFloorAndCeil(houses []int, target int) (int, int) {
    floor := -1
    ceil := -1
    for _, house := range houses {
        if house = target && ceil == -1 {
            ceil = house
            break
        }
    }
    return floor, ceil
}

func main() {
    houses := []int{2, 5, 8, 12, 16, 23, 38, 56, 72, 91}
    target := 20
    // Call findFloorAndCeil and print the result
    // Your code here
}

Hint

Use floor, ceil := findFloorAndCeil(houses, target) and fmt.Printf("Floor: %d, Ceil: %d\n", floor, ceil).