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❮ C Exercise Example74 C Exercise Example23 ❯

C Exercise Example 68

C Language Classic 100 Examples

Title: There are n integers, which should be shifted such that each number moves m positions backward, and the last m numbers become the first m numbers.

Program Analysis: None.

Example

//  Created by www.tutorialpro.org on 15/11/9.
//  Copyright © 2015 tutorialpro.org. All rights reserved.
//

#include <stdio.h>
#include <stdlib.h>
int main()
{
    int arr[20];
    int i,n,offset;
    // Input array size and array content
    printf("Total numbers?\n");
    scanf("%d",&n);
    printf("Input %d numbers.\n",n);
    for(i=0;i&lt;n;i++)
        scanf("%d",&arr[i]);
    // Input shift offset
    printf("Set your offset.\n");
    scanf("%d",&offset);
    printf("Offset is %d.\n",offset);
    // Print array before shift
    print_arr(arr,n);
    // Shift array and print
    move(arr,n,offset);
    print_arr(arr,n);
}

// Print array
void print_arr(int array[],int n)
{
    int i;
    for(i=0;i&lt;n;++i)
        printf("%4d",array[i]);
    printf("\n");
}
// Shift array
void move(int array[],int n,int offset)
{
    int *p,*arr_end;
    arr_end=array+n;      // Next position after the last element of the array
    int last;

    // Shift until offset is 0
    while(offset)
    {
        last=*(arr_end-1);
        for(p=arr_end-1;p!=array;--p)   // Shift one position to the right
            *p=*(p-1);
        *array=last;
        --offset;
    }
}

C Language Classic 100 Examples

❮ C Exercise Example74 C Exercise Example23 ❯