Little Endian to Big Endian

#include <stdio.h>
#include <stdint.h>

uint32_t convert_endian(uint32_t value) {
    uint32_t r = 0;
    for (int i = 0; i < 4; i++) {
        if (i > 0) r = r << 8;
        r |= ((value >> (8*i)) & 0x000000FF);
    }
    return r;
}

int main() {
    uint32_t val;
    scanf("%u", &val);
    printf("%u", convert_endian(val));
    return 0;
}