进制转换
//反转字符串
+ (NSString*)fanZhuan:(NSString*)str{
unsignedlonglen;
len = [strlength];
unichara[len];
for(inti =0; i < len; i++)
{
unicharc = [strcharacterAtIndex:len-i-1];
a[i] = c;
}
return[NSStringstringWithCharacters:alength:len];
}
//十进制转二进制
+ (NSString*)toBinarySystemWithDecimalSystem:(NSString*)decimal With:(int)length
{
NSString* temStr =@"";
NSString* result =@"";
intnum = [decimalintValue];
intremainder =0;//余数
intdivisor =0;//除数
while(true)
{
remainder = num%2;
divisor = num/2;
num = divisor;
temStr = [temStrstringByAppendingFormat:@"%d",remainder];
if(divisor ==0)
{
break;
}
}
for(inti = (int)(temStr.length-1); i >=0; i --)
{
result = [resultstringByAppendingFormat:@"%@",
[temStrsubstringWithRange:NSMakeRange(i ,1)]];
}
if(result.length<= length)
{
NSMutableString*b = [[NSMutableStringalloc]init];;
for(inti =0; i < length - result.length; i++)
{
[bappendString:@"0"];
}
return[selffanZhuan:[bstringByAppendingString:result]];
}
else
{
return[selffanZhuan:result];
}
}
//二进制转十进制
+ (NSString*)toDecimalSystemWithBinarySystem:(NSString*)binary
{
NSString* temStr = [selffanZhuan:binary];
intll =0;
inttemp =0;
for(inti =0; i < temStr.length; i ++)
{
temp = [[temStrsubstringWithRange:NSMakeRange(i,1)]intValue];
temp = temp *powf(2, temStr.length- i -1);
ll += temp;
}
NSString* result = [NSStringstringWithFormat:@"%d",ll];
returnresult;
}
