Set 01-02.find sum of weights based on the following conditions.c

/* Given a set of numbers like <10,36,54,89,12> we want to find sum of weights based on the following conditions
    1. 5 if a perfect square
    2. 4 if multiple of 4 and divisible by 6
    3. 3 if even number

And sort the numbers based on the weight and print it as follows

<10,its_weight>,<36,its weight><89,its weight>

Should display the numbers based on increasing order*/
#include<stdlib.h>
#include<stdio.h>
int check(int);
int main(void)
{
	int *a,i,j,n;
	printf("Array size : ");
        scanf("%d",&n);
        a=malloc(sizeof(int)*n);
           printf("Enter array elements : ");
        for(i=0;i<n;i++)
            scanf("%d",&a[i]);
	printf("Array elements : ");
        for(i=0;i<n;i++)
            printf("%d ",a[i]);
	for(i=0;i<n-1;i++)
		for(j=0;j<n-i-1;j++)
			if(check(a[j])>check(a[j+1]))
				a[j]=a[j]+a[j+1]-(a[j+1]=a[j]);
	printf("The elements after sorting with its weight is : \n");
	for(i=0;i<n;i++)
		printf("< %d , %d >\n",a[i],check(a[i]));
        free(a);
	return 0;
}

int check(int n)
{
	int sum,weight=0,i;
	for(sum=0,i=1;i<n;i+=2)
	{
		sum=sum+i;
		if(sum==n)
			weight+=5;
	}
	if(n%4==0 && n%6==0)
		weight+=4;
	if(n%2==0)
		weight+=3;
	return weight;
}