114. Little Endian to Big Endian

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

typedef union {
    uint32_t value;
    uint8_t bytes[4];
} Reg32;

uint32_t convert_endian(uint32_t value) {
    // Write logic to swap bytes
    Reg32 reg;
    uint8_t hold;

    reg.value= value;

    hold= reg.bytes[0];
    reg.bytes[0]= reg.bytes[3];
    reg.bytes[3]= hold;

    hold= reg.bytes[1];
    reg.bytes[1]= reg.bytes[2];
    reg.bytes[2]= hold;

    return reg.value;
}

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

Solving Approach

use a union typpe definition to swap the bytes