Thread: removing duplicate elements from an array

hello everyone,
while removing duplicate elements from an array, if more than 4 array elements are same then removal does not work. however my logic seems to be alright. i reckon there is a problem with the conditions and assignments in the three for loops that i have used. the program is as follows:

Code:

/*c program to remove duplicate elements in an array*/
#include<stdio.h>
int main(void)
{
     int array[30],i,j,k,n;
     printf("\n How many elements:");
     scanf("%d",&n);
     printf("\n Enter the elements in the array:");
     for(i=1;i<=n;i++)
     {
          scanf("%d",&array[i]);
     }
	  for(i=1;i<=n-1;i++)/*main loop*/
	  {
          for(j=i+1;j<=n;j++)/*secondary loop with which the elements of the main loop will be compared*/
                               /*since the comparison will be between ith and the (i+1)th element thatswhy j=i+1*/   
          {
                if(array[i]==array[j])/*if any element of the main loop is found to be equal to any element of the secondary loop*/ 
                {
                     for(k=j;k<=n;k++)/*loop to shift the elements of the array one place leftwards to take the place of the 
                                        removed duplicate element*/
                     {
                           array[k]=array[k+1];/*the assignment to facilitate the newly arranged array*/
                     }
                     i=1;/*once the array has been rearranged main loop rebegins to check duplicacy in
                           case there are more than 1 duplicate elements or more than 1 instance of the same element*/ 
                     n--;/*for each removal of any duplicate element the number of total elements in array decreases by 1*/
                }
          }
     }
     printf("\n Array after removing duplicate elements is:");
     for(i=1;i<=n;i++)
     {
          printf("\t %d",array[i]);/*printing the pruned array*/
     }
     return 0;
}

take for instance if the input elements are 1,1,1,1,1,2,2,3,5 then after removal of duplicacy the array is 1,1,2,3,5. please help!

Say you compare i=1 and j=2 and find they are the same. You move things over to the left to crunch the duplicate; but the next pass goes with i=1 and j=3. However, i=1 has not been checked against the *new* j=2....