ttoi 支持16进制（0xnumber），8进制（0number），10进制（number）

最新推荐文章于 2019-07-26 23:16:12 发布

原创最新推荐文章于 2019-07-26 23:16:12 发布 · 1.6k 阅读

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CC 4.0 BY-SA版权

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#c #include #float #null

本文介绍了一种将字符串形式的数值转换为整数的方法，包括处理不同进制（如十六进制、八进制和十进制）的能力，并考虑了字符串输入的各种情况，如前缀标识符。

#include <math.h>
int ssCtoi(TCHAR c, int rad)
{
if( (c >= TEXT('a') && c <= TEXT('f')) )
{
  if(rad >= 16)
  {
   return c - TEXT('a') + 10;
  }
}else if((c >= TEXT('A') && c <= TEXT('F')))
{
  if(rad >= 16)
  {
   return c - TEXT('A') + 10;
  }
}else if(c >= TEXT('8') && c <= TEXT('9'))
{
  if(rad == 10 || rad == 16)
  {
   return c - TEXT('0');
  }
}else if(c >= TEXT('0') && c <= TEXT('7'))
{
  return c - TEXT('0');
}

return 0;
}
int ssTtoi(LPCTSTR lpTextValue)
{
if(lpTextValue == NULL || _tcslen(lpTextValue) <= 0)
{
return 0;
}

LPCTSTR lpCurValuePointer = lpTextValue;

int rad = 10;

if(_tcslen(lpCurValuePointer) <= 0)
{
return 0;
}

if( lpCurValuePointer[0] == TEXT('0') && (lpCurValuePointer[1] == TEXT('x') || lpCurValuePointer[1] == TEXT('X')) )
{
  lpCurValuePointer += 2;
  rad = 16;
}else if(lpCurValuePointer[0] == TEXT('0'))
{
  lpCurValuePointer++;
  rad = 8;
}

LPCTSTR lpValuePointerEnd = lpCurValuePointer;
while(lpValuePointerEnd[0] != TEXT('/0'))
{
  if( (lpValuePointerEnd[0] >= TEXT('a') && lpValuePointerEnd[0] <= TEXT('f'))
   || (lpValuePointerEnd[0] >= TEXT('A') && lpValuePointerEnd[0] <= TEXT('F')) )
  {
   if(rad != 16)
    break;
  }else if(lpValuePointerEnd[0] >= TEXT('8') && lpValuePointerEnd[0] <= TEXT('9'))
  {
   if(rad != 10 && rad != 16)
    break;
  }else if(lpValuePointerEnd[0] >= TEXT('0') && lpValuePointerEnd[0] <= TEXT('7'))
  {

  }else{
   break;
  }

lpValuePointerEnd++;
}
if(lpValuePointerEnd <= lpCurValuePointer)
{
return 0;
}

int nRetValue = 0;

int nEx = 0;

while( --lpValuePointerEnd >= lpCurValuePointer )
{
nRetValue += (ssCtoi(*lpValuePointerEnd, rad) * pow((float)rad, nEx++));
}

return nRetValue;

}