C Exercises: Find the ceiling in a sorted array

C Array: Exercise-40 with Solution

Write a program in C to find the ceiling in a sorted array.
N.B.: Given a sorted array in ascending order and a value x, the ceiling of x is the smallest element in array greater than or equal to x, and the floor is the greatest element smaller than or equal to x.

Visual Presentation:

Sample Solution:

C Code:

#include <stdio.h>

// Function to find the ceiling of a given element 'x' in the array
int findCeiling(int arr1[], int low, int high, int x) {
    int i;
    // If 'x' is smaller or equal to the first element, return the index of the first element
    if (x <= arr1[low])
        return low;

    // Traverse the array
    for (i = low; i < high; i++) {
        // If 'x' is found in the array, return its index
        if (arr1[i] == x)
            return i;

        // If 'x' is between two elements, return the index of the next greater element
        if (arr1[i] < x && arr1[i + 1] >= x)
            return i + 1;
    }
    return -1; // If no ceiling exists, return -1
}

int main() {
    int arr1[] = {1, 3, 4, 7, 8, 9, 9, 10};
    int ctr = sizeof(arr1) / sizeof(arr1[0]);
    int x = 5, i;

    // Print original array
    printf("The given array is :  ");
    for (i = 0; i < ctr; i++) {
        printf("%d  ", arr1[i]);
    } 
    printf("\n");

    // Find the ceiling of 'x' in the array
    int index = findCeiling(arr1, 0, ctr - 1, x);

    // Display the result
    if (index == -1)
        printf("No ceiling for the number %d exists in the array. ", x);
    else
        printf("The ceiling of %d is: %d", x, arr1[index]);

    getchar(); // To keep the console window open
    return 0;
}

Sample Output:

The given array is :  1  3  4  7  8  9  9  10  
The ceiling of 5 is: 7 

Flowchart:

C Programming Code Editor:

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