// 第一種算法，從低位到高位掃描移位，需要一個(gè)數(shù)組輔助倒序，一次性輸出結(jié)果 
 
#include <stdio.h> 
 
#define MAX_HEX_NUM 16 
#define OUT_DATA_LEN sizeof(int)*2 // 2個(gè)16進(jìn)制數(shù)表示1個(gè)字節(jié)
 
static char Hex_Char_Table[MAX_HEX_NUM] = { 
  '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F' 
}; 
 
int ten2hex( int data ) 
{ 
  char result[OUT_DATA_LEN+1]; 
  int i,index; 
 
  result[OUT_DATA_LEN] = '\0'; 
  for( i=OUT_DATA_LEN-1; i>=0; i-- ) 
  { 
    index = data & 0xf; 
    result[i] = Hex_Char_Table[index]; 
    data = data>>4; 
  } 
 
  printf("0x%s\n",result); 
 
  return 0; 
} 

#include <stdio.h> 
 
#define BITS_OF_INT  sizeof(int)*8 // int的位數(shù) 
#define OUT_DATA_LEN sizeof(int)*2 // 2個(gè)16進(jìn)制數(shù)表示1個(gè)字節(jié) 
 
int printHex( int num ) 
{ 
  int i; 
 
  printf("0x"); 
  for(i=0;i<OUT_DATA_LEN;i++) 
  { 
    unsigned int res = num & 0xf0000000; //注意，必須用 unsigned int來接收，否則當(dāng)輸入負(fù)數(shù)的時(shí)候會轉(zhuǎn)換錯(cuò)誤 
    res = res >> (BITS_OF_INT-4); 
    char c; 
    if( res <= 9 ) 
      c = res + '0'; 
    else 
      c = 'A' + res - 10; 
 
    printf("%c",c); 
 
    num = num << 4; 
  } 
 
  printf("\n"); 
}