1.字符編碼
//字節和字符的區別 http://jiapumin.iteye.com/blog/1006144 getBytes和操作系統編碼格式相關聯的
import java.io.UnsupportedEncodingException;
public class Test01 {
public static void main(String[] args) throws UnsupportedEncodingException {
String gb=new String("中國".getBytes(),"gb2312");
System.out.println(gb);
String ios=new String(gb.getBytes("gb2312"),"ISO-8859-1");
System.out.println(ios); //原本編碼格式轉換成另外一種以後也是可能出現亂碼的
gb=new String(ios.getBytes("ISO-8859-1"),"gb2312");
System.out.println(gb);
//在IDEA中上面的中國都是亂碼，只有在使用了utf-8以後纔不是亂碼 主要的原因在於ISO-8859-1沒有對應的中文符號
String gb2=new String("中國".getBytes(),"utf-8");
System.out.println(gb2);
String ios2=new String(gb2.getBytes("utf-8"),"ISO-8859-1");
System.out.println(ios2);
gb2=new String(ios2.getBytes("ISO-8859-1"),"utf-8");
System.out.println(gb2);
}
}2.曾經項目中utf-b和ansi編碼格式轉換代碼：
#include <iostream>
#include <string>
#include <Windows.h>
using namespace std;
/*首先明確一點：ansi轉utf8編碼，不能直接相互轉換，只能是經過unicode編碼格式。*/
/*別人分解版本*/
string Unicode2Ascii(wstring wstrsrc);
wstring Ascii2Unicode(string astrsrc);
string Unicode2UTF8(wstring wstrsrc);
wstring UTF82Unicode(string utf8strsrc);
/*自己版本*/
string FromUtf8ToAnsi(const string& str)
{
//從utf-8到unicode編碼轉換
int len = 0;
len = str.length();
int unicodeLen = ::MultiByteToWideChar(CP_UTF8,NULL,str.c_str(),-1,NULL,0 );
wchar_t * pUnicode;
pUnicode = new wchar_t[unicodeLen+1];
memset(pUnicode,0,(unicodeLen+1)*sizeof(wchar_t));
::MultiByteToWideChar( CP_UTF8,NULL,str.c_str(),-1,(LPWSTR)pUnicode,unicodeLen );
wstring rt;
rt = ( wchar_t* )pUnicode;
delete pUnicode;
//return rt;
//從unicode到ansi編碼轉換
char *pElementText;
int iTextLen;
iTextLen = WideCharToMultiByte( CP_ACP,NULL,rt.c_str(),-1,NULL,0,NULL,NULL );
pElementText = new char[iTextLen + 1];
memset( ( void* )pElementText, 0, sizeof( char ) * ( iTextLen + 1 ) );
::WideCharToMultiByte( CP_ACP,0,rt.c_str(),-1,pElementText,iTextLen,NULL,NULL );
string strText;
strText = pElementText;
delete[] pElementText;
return strText;
}
//字符串從utf-8編碼到ansi編碼
string changestringencodingFromUtf8ToAnsi(const string& utf8str)
{
string utf8str2 =utf8str;
string ansistr ="";
ansistr=FromUtf8ToAnsi(utf8str2);
return ansistr;
}
string FromAnsitoUtf8(const string& ansistr)
{
//ansi到unicode編碼轉換
string ansistr2=ansistr;
int sLen = MultiByteToWideChar(CP_ACP, NULL, ansistr2.c_str(), -1, NULL, 0);
wchar_t* sUnicode = new wchar_t[sLen];
//wchar_t* sUnicode = (wchar_t*)malloc(sLen*sizeof(wchar_t));
MultiByteToWideChar(CP_ACP, NULL, ansistr2.c_str(), -1, sUnicode, sLen);
//wstring rt;
//rt = ( wchar_t* )sUnicode;
//delete sUnicode;
//從unicode編碼到ansi編碼轉換
//wchar_t *sUnicode = L"Convert Unicode to ANSI, Unicode 轉換爲 ANSI";
int sLen2 = WideCharToMultiByte(CP_ACP, NULL, sUnicode, -1, NULL, 0, NULL, NULL);
char* sAnsi = new char[sLen2];
//char* sAnsi = (char*)malloc(sLen);
WideCharToMultiByte(CP_ACP, NULL, sUnicode, -1, sAnsi, sLen2, NULL, NULL);
string strText;
strText = sAnsi;
delete[] sAnsi;
return strText;
}
//字符串從ansi編碼到utf-8編碼
string changestringencodingFromAnsiToUtf8(const string& ansistr)
{
string ansistr2 =ansistr;
string ansistr3 ="";
ansistr3=FromAnsitoUtf8(ansistr2);
return ansistr3;
}
int main(int argc, char* argv[])
{
char szText[] = "這是一個ANSI轉化爲UTF8的例子!\r\n";
wstring strUnicode;
string strAnsi, strUTF8;
strAnsi = szText;
strUnicode = Ascii2Unicode(strAnsi);
strUTF8 = Unicode2UTF8(strUnicode);
cout << strUTF8 << endl;
strUnicode = UTF82Unicode(strUTF8);
strAnsi = Unicode2Ascii(strUnicode);
cout << strAnsi << endl;
/*char szText[] = "這是一個ANSI轉化爲UTF8的例子!\r\n";
string strutf8="";
string stransi="";
strutf8=changestringencodingFromAnsiToUtf8(szText);
cout<<strutf8<<endl;
stransi=changestringencodingFromUtf8ToAnsi(strutf8);
cout<<stransi<<endl;*/
return 0;
}
string Unicode2Ascii(wstring wstrsrc)
{
int nLength = ::WideCharToMultiByte(CP_OEMCP, 0, wstrsrc.c_str(), -1, NULL, 0, NULL, NULL);
if(nLength <= 0) return string("");
char *szbuffer = new char[nLength + 2];
::WideCharToMultiByte(CP_OEMCP, 0, wstrsrc.c_str(), -1, szbuffer, nLength, NULL, NULL);
string strnew = szbuffer;
delete [] szbuffer;
return strnew;
}
wstring Ascii2Unicode(string astrsrc)
{
int nLength = ::MultiByteToWideChar(CP_ACP, 0, astrsrc.c_str(), -1, NULL, 0);
if(nLength <= 0) return wstring(L"");
wchar_t *szbuffer = new wchar_t[nLength + 2];
::MultiByteToWideChar(CP_ACP, 0, astrsrc.c_str(), -1, szbuffer, nLength);
wstring strnew = szbuffer;
delete [] szbuffer;
return strnew;
}
string Unicode2UTF8(wstring wstrsrc)
{
int nLength = ::WideCharToMultiByte(CP_UTF8, 0, wstrsrc.c_str(), -1, NULL, 0, NULL, NULL);
if(nLength <= 0) return string("");
char *szbuffer = new char[nLength + 2];
::WideCharToMultiByte(CP_UTF8, 0, wstrsrc.c_str(), -1, szbuffer, nLength, NULL, NULL);
string strnew = szbuffer;
delete [] szbuffer;
return strnew;
}
wstring UTF82Unicode(string utf8strsrc)
{
int nLength = ::MultiByteToWideChar(CP_UTF8, 0, utf8strsrc.c_str(), -1, NULL, 0);
if(nLength <= 0) return wstring(L"");
wchar_t *szbuffer = new wchar_t[nLength + 2];
::MultiByteToWideChar(CP_UTF8, 0, utf8strsrc.c_str(), -1, szbuffer, nLength);
wstring strnew = szbuffer;
delete [] szbuffer;
return strnew;
}3.c++內置反轉函數
#include <iostream> // std::cout
#include <algorithm> // std::reverse
#include <vector> // std::vector
int main() {
std::vector<int> myvector;
// set some values:
for (int i = 1; i < 10; ++i) myvector.push_back(i); // 1 2 3 4 5 6 7 8 9
std::reverse(myvector.begin(), myvector.end()); // 9 8 7 6 5 4 3 2 1
// print out content:
std::cout << "myvector contains:";
for (std::vector<int>::iterator it = myvector.begin(); it != myvector.end(); ++it)
std::cout << ' ' << *it;
std::cout << '\n';
return 0;
}
----------------------------------------------------------------------------------
// string::rbegin/rend
#include <iostream>
#include <string>
int main ()
{
std::string str ("now step live...");
for (std::string::reverse_iterator rit=str.rbegin(); rit!=str.rend(); ++rit)
std::cout << *rit;
return 0;
}
---------------------------------------------------------------------------------
#include <iostream>
#include<String>
using namespace std;
int main(){
string text="i am student!";
text=string(text.rbegin(),text.rend());
cout<<text<<endl;
return 0;
}1.
public class Solution {
public String reverseString(String s) {
char[] word = s.toCharArray();
int i = 0;
int j = s.length() - 1;
while (i < j) {
char temp = word[i];
word[i] = word[j];
word[j] = temp;
i++;
j--;
}
return new String(word);
}
}
2.
public class Solution {
public String reverseString(String s) {
byte[] bytes = s.getBytes();
int i = 0;
int j = s.length() - 1;
while (i < j) {
byte temp = bytes[i];
bytes[i] = bytes[j];
bytes[j] = temp;
i++;
j--;
}
return new String(bytes);
}
}
//異或操作運算符
3.
public class Solution {
public String reverseString(String s) {
char[] word = s.toCharArray();
int i = 0;
int j = s.length() - 1;
while (i < j) {
word[i] = (char) (word[i] ^ word[j]);
word[j] = (char) (word[i] ^ word[j]);
word[i] = (char) (word[i] ^ word[j]);
i++;
j--;
}
return new String(bytes);
}
}
4.
public class Solution {
public String reverseString(String s) {
byte[] bytes = s.getBytes();
int i = 0;
int j = s.length() - 1;
while (i < j) {
bytes[i] = (byte) (bytes[i] ^ bytes[j]);
bytes[j] = (byte) (bytes[i] ^ bytes[j]);
bytes[i] = (byte) (bytes[i] ^ bytes[j]);
i++;
j--;
}
return new String(bytes);
}
}
//Java library
5.
class Solution {
public:
string reverseString(string s) {
s=string(s.rbegin(),s.rend());
return s;
}
};
6.
public class Solution {
public String reverseString(String s) {
return new StringBuilder(s).reverse().toString();
}
}
//分治 遞歸
7.
public class Solution {
public String reverseString(String s) {
int length = s.length();
if (length <= 1) return s;
String leftStr = s.substring(0, length / 2);
String rightStr = s.substring(length / 2, length);
return reverseString(rightStr) + reverseString(leftStr);
}
}
