C Exercises: Array fill, replace each subsequent position of the array by the double value of the previous

Last update on September 19 2025 12:45:15 (UTC/GMT +8 hours)

Replace first element of array and double subsequent values

Write a C program that reads an array of integers (length 7), and replaces the first element of the array by a given number and replaces each subsequent position of the array by the double value of the previous.

Sample Solution:

C Code:

#include <stdio.h>

int main () {
    int array_nums[7], i, x, k;

    // Prompt user for the first element of the array
    printf("Input the first element of the array:\n");
    scanf("%d", &x);

    // Loop to generate array elements by doubling 'x' in each iteration
    for (k = 0, i = x; k < 7; i *= 2, k++) {
        array_nums[k] = i; // Assign the calculated value to the array
    }

    // Print a message indicating the array elements will be displayed
    printf("\nArray elements:\n");

    // Loop to print each element of the array
    for (i = 0; i < 7; i++) {
        printf("array_nums[%d] = %d\n", i, array_nums[i]);
    }

    return 0; // End of program
}

Sample Output:

Input the first element of the array:
5

Array elements:
array_nums[0] = 5
array_nums[1] = 10
array_nums[2] = 20
array_nums[3] = 40
array_nums[4] = 80
array_nums[5] = 160
array_nums[6] = 320

Flowchart:

C Programming Flowchart: Array fill, replace each subsequent position of the array by the double value of the previous.

For more Practice: Solve these Related Problems:

Write a C program to read an array and update it so that each element (except the first) becomes twice its previous element.
Write a C program to perform in-place modification of an array where the first element is set and each following element is its double.
Write a C program to use recursion to replace each element in an array with double the previous element starting from a given number.
Write a C program to implement a function that updates an array such that every element after the first is the double of its predecessor.

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