convert decimal to binary in c

1#include <stdio.h>
2
3void main()
4{
5    int n;
6    long long bin = 0;
7    int j,rem, i = 1;
8
9    printf("Enter a decimal number: ");
10    scanf("%d", &n);
11
12
13    for(j=n;j!=0;j)
14    {
15        rem = j % 2;
16        j /= 2;
17        bin += rem * i;
18        i *= 10;
19    }
20
21    printf("%d in decimal = %lld in binary",n,bin);
22}

1#include <math.h>
2#include <stdio.h>
3int convert(long long n);
4int main() {
5    long long n;
6    printf("Enter a binary number: ");
7    scanf("%lld", &n);
8    printf("%lld in binary = %d in decimal", n, convert(n));
9    return 0;
10}
11
12int convert(long long n) {
13    int dec = 0, i = 0, rem;
14    while (n != 0) {
15        rem = n % 10;
16        n /= 10;
17        dec += rem * pow(2, i);
18        ++i;
19    }
20    return dec;
21}
22

1#include <stdio.h>
2#include <math.h>
3#include <stdlib.h>
4
5#define D 10
6
7int main()
8{
9	int i, n, k, vet[D];
10   
11	printf("FROM DECIMALS TO BINARIES\nEnter decimal: ");
12	scanf("%d", &n);
13   
14	k = 0;
15   
16	while (n != 0)
17	{
18		if ((n % 2) == 1) 
19			vet[k] = 1;
20		else
21			vet[k] = 0;
22          
23		n /= 2;
24       
25		k++;
26	}
27	
28	printf("Transformed into binary: ");
29    
30	for(i = k - 1; i >= 0; i --)
31		printf("%d", vet[i]);
32		
33	printf("\n\n");
34    
35	system("pause");
36}