整数与字符串互转

//整数转换成字符串——IntToString.h#ifdef __cplusplusextern "C"{#endif#ifndef __INT_TO_STRING__#define __INT_TO_STRING__char* IntToString(int num,char* str,int radix){    //索引表    char index[] = "0123456789ABCDEF";    unsigned ui_num;//将int——》unsigned的中间值    int i_index = 0;//char中的地址偏移量    if( radix == 10 && num < 0 )//十进制负数转为正数    {        ui_num = (unsigned)-num;        str[i_index++] = '-';    }    else     {        ui_num = (unsigned)num;    }    do{        str[i_index++] = index[ui_num % radix];        ui_num /= radix;    }while(ui_num != 0);    str[i_index] = '\0';    i_index--;    int j = 0 ,sign = 0;    if ( str[0] == '-')    {        j = 1;        sign = 1;    }    for( ; j <= i_index /2 ; j++)    {        char temp = str[j];        str[j] = str[i_index-j+sign];        str[i_index-j+sign] = temp;    }    return str;}enum int_flag{uncorrect,correct};int g_flag = uncorrect;int StringToInt(const char* str){    int postive = 1;    int i_firstIn = 0;    unsigned int result = 0;    if( str == NULL )    {        return 0;    }    while(*str < '1' || *str > '9')//如果不是1—9之间的数，则进行判断    {           if (*str == ' ' || *str == '0')//如果是空格或是0，则继续找        {                       str++;            continue;        }        else if (*str == '+' || *str == '-')        {            i_firstIn++;            if(i_firstIn > 1)//如果+号和-号多于1个则退出            { break; }            if(*str == '-')            { postive = -1;}            str++;        }        else        {                           break;//退出        }    }    if(i_firstIn > 1)//如果+号和-号多于1个则退出    {        return 0;     }    //输入的字符串符合转换要求    while (*str != '\0')    {        g_flag = correct;        if (*str >= '0' && *str <= '9')//字符在0-9之间则转换        {            result = 10 * result + (*str - '0');            str++;            if ( (postive == -1 && result > (1<<(sizeof(int)*8-1)) ) ||                (postive == 1 && result > ~(1<<(sizeof(int)*8-1))) )//数据超出int类型的范围            {                g_flag = uncorrect;                result = 0;                break;            }        }        else//字符不在0-9之间则退出        {            break;        }    }    return (postive == 1) ? result :(int)(0 - result);}#endif#ifdef __cplusplus}#endif