#include <stdint.h>/* take 64 bits of data in v[0] and v[1] and 128 bits of key[0] - key[3] */void encipher(unsigned int num_rounds, uint32_t v[2], uint32_t const key[4]) {    unsigned int i;    uint32_t v0=v[0], v1=v[1], sum=0, delta=0x9E3779B9;    for (i=0; i < num_rounds; i++) {        v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + key[sum & 3]);        sum += delta;        v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + key[(sum>>11) & 3]);    }    v[0]=v0; v[1]=v1;}void decipher(unsigned int num_rounds, uint32_t v[2], uint32_t const key[4]) {    unsigned int i;    uint32_t v0=v[0], v1=v[1], delta=0x9E3779B9, sum=delta*num_rounds;    for (i=0; i < num_rounds; i++) {        v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + key[(sum>>11) & 3]);        sum -= delta;        v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + key[sum & 3]);    }    v[0]=v0; v[1]=v1;}