Question

Write a C program to assign natural numbers 1 to 100 into a one-dimensional integer array. Display all the values in the array on the screen.

For each number in the array, determine if the number contains digit 7 or is divisible by 7. Display all those numbers on the screen.

Original array: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51
52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78
79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100

Numbers containing digit 7 or divisible by 7:
7 14 17 21 27 28 35 37 42 47 49 56 57 63 67 70 71 72 73 74 75 76 77 78 79 84 87
91 97 98

Answer 1

#include <stdio.h>

int main() {
    int i, arr[100];
    for (i = 0; i < 100; ++i) {
        arr[i] = i+1;
    }
    printf("Original array: ");
    for (i = 0; i < 100; ++i) {
        printf("%d ", arr[i]);
    }
    printf("\n\nNumbers containing digit 7 or divisible by 7:\n");
    for (i = 0; i < 100; ++i) {
        if (arr[i] % 7 == 0 || arr[i] % 10 == 7 || arr[i] / 10 == 7) {
            printf("%d ", arr[i]);
        }
    }
    printf("\n");
    return 0;
}