LONELY INTEGER

Program:to find number occurring only once

If there are integers in an array,you have to find out the numer that occurs only once

Input Format

The first line of the input indicates the number of integers. 
The next line is integers that form the array.

#include <stdio.h>

#include <string.h>

#include <math.h>

#include <stdlib.h>

int lonelyinteger(int a_size, int* a) {

    int a_count[100],i,count=0,c;

   for(i=0;i< 100;i++)

       {

       a_count[i]=0;

       }

    for(i=0;i< a_size;i++)

        {c=*(a+i);

        a_count[c]=(a_count[c])+1;

        }

    for(i=0;i< 100;i++)

        {

           if(a_count[i]==1)

            {return (i); }

        }

   

   

return count;

}

int main() {

    int res;

   

    int _a_size, _a_i;

    scanf("%d", &_a_size);

    int _a[_a_size];

    for(_a_i = 0; _a_i < _a_size; _a_i++) {

        int _a_item;

        scanf("%d", &_a_item);

       

        _a[_a_i] = _a_item;

    }

   

    res = lonelyinteger(_a_size, _a);

    printf("%d", res);

   

    return 0;

}