482. License Key Formatting C# o(n) 无法通过，求优化

显示：34 / 38 test cases passed.

求优化

[mw_shl_code=objc,true]public class Solution {

public string LicenseKeyFormatting(string S, int K) {

S=S.ToUpper();

string result="";

int p=S.Length-1;

while(p>=0){

int cnt=K;

string ss="";

while(cnt>0 && p>=0){

if(S=='-'){

p--;

}

else{

ss=S+ss;

p--;

cnt--;

}

}

if(ss!=""){

result='-'+ss+result;

}

}

return result.Substring(1);

}

}[/mw_shl_code]