dec2bin in C without using arrays

dec2bin-no-arrays.c

#include <stdio.h>
#include <math.h>

int main(int argc, char *argv[]) {
    int dec;
    scanf("%d", &dec);


    // figure out bits needed to represent number
    // 1. you can log(dec) base 2 or...
    // 2. what ill do next

    int pot = 0;
    while(pow(2, pot) <= dec) {
        pot++;
    }
    pot--; // you always go one further (edge case 1024 for example)

    for(int i = pot; i >= 0; i--) {
        // does 2**i fit in dec?
        if(pow(2, i) <= dec) {
            printf("1");
            dec -= pow(2, i);
        } else {
            printf("0");
        }
    }
    printf("\n");
    return 0;
}