在写一个函数，根据两文件的绝对路径算出相对路径。如 a="

string fun(string str1, string str2)
{
    string temp = "";
    bool flag = false;
    int j;
    for (int i = 0; i < str1.size(); i++)
    {
        if (!flag && str1[i] != str2[i])
        {
            flag = true;
            j = i;
        }
        if (flag && str1[i] == '/')
        {
            temp += "../";
        }
    }
    if (temp == "") temp += '/';
    temp += str2.substr(j);
    return temp;
}

源码：

public class RelativePath {

	public static void main(String[] args) {
		
		String a="/qihoo/app/a/b/c/d/new.c";
		String b="/qihoo/app/a/b/c/d/new.c/1/2/test.c";
		String sb=getRelativePath(a, b);
		System.out.println(sb);
	}
	public static String getRelativePath(String a, String b){
		StringBuffer sb=new StringBuffer();
		String newA=a.substring(1);
		String newB=b.substring(1);
		String[] newAs=newA.split("/");
		String[] newBs=newB.split("/");
		int start=-1,end=0;
		int len=newAs.length>newBs.length?newBs.length:newAs.length;
		boolean flag=false;
		for(int i=0;i<newAs.length;i++){
			if(newAs[i].equals(newBs[0]) && flag==false){
				flag=true;
				start=i;
				break;
			}
		}	
		for(int j=0;j<len;j++){
			if(!newAs[start+j].equals(newBs[j])){
				end=j;
				break;
			}
		}
		for(int k=start;k<start+end;k++){
			sb.append("../");
		}
		for(int k=end;k<newBs.length;k++){
			sb.append(newBs[k]).append("/");
		}
		return sb.substring(0, sb.length()-1);
	}
}

string Path( string b , string a )

{

    int size= b .size()< a .size()? b .size(): a .size();

    int i=1;

    int last=0;

    for (;i<size;i++)

    {

       if ( b [i]== a [i])

       {

           if ( b [i]== '/' )

           {

              last=i;

              continue ;

           }

       }

       else

       {

           break ;

       }

    }

    int num=0;

    for ( int j= a .size()-1;j>last;j--)

    {

       if ( a [j]== '/' )

       {

           num++;

       }

    }

    string str= "../" ;

    string res= "" ;

    for ( int i=0;i<num;i++)

    {

       res+=str;

    }

    for ( int j=last+1;j< b .size();j++)

    {

       res+= b [j];

    }

    return res;

}

string fun(string str1, string str2)//str2相对于str1的相对路径
{
    string result;
    if(str1.size() == 0)
    {
        return str2;
    }
    if(str2.size() == 0)
    {
        return result;
    }

    size_t j = 0;
    for(size_t i = 0; i <str1.size(); ++i)
    {
        if(str1[i] != str2[i])
        {
            break;
        }

        if(str1[i] == '/')
        {
            j = i;
        }
    }

    result = str2.substr(j + 1);

    int counter = 0;
    for(size_t k = j + 1; k < str1.size(); ++k)
    {
        if(str1[k] == '/')
        {
            ++counter;
        }
    }

    string temp;
    for(size_t i = 0; i < counter; ++i)
    {
        temp += "../";
    }
    result = temp + result;
    return result;
}

 <?php

function relativePath($aPath, $bPath) {
	$aArr = explode('/', $aPath);    //explode函数用于切分字符串,返回切分后的数组,此处用'/'切分字符串
	$bArr = explode('/', $bPath);
	$path = '';
	for($i=0;$i < count($bArr);$i++){
		if($aArr[$i] == $bArr[$i]){
			$path .='../';
			//$bArr[$i] = '';
			unset($bArr[$i]);
		}
	
	}                
	$path .=implode('/',$bArr);
	return $path;

}   

	echo relativePath('/qihoo/app/a/b/c/d/new.c', '/qihoo/app/1/2/test.c');

?>

using namespace std;

}

/**
 * 在写一个函数，根据两文件的绝对路径算出相对路径。如 a="/qihoo/app/a/b/c/d/new.c",b="/qihoo/app/1/2/test.c'，那么b相对于a的相对路径是"../../../../1/2/test.c"
 * @author luchunlong
 *
 * 2015年8月10日 下午1:49:02
 */
public class AbsoluteToRelativeLocation {
	
	public String convert(String path1,String path2){
		String result="";               
		path1.substring(1);                    //第一步，先除掉绝对路径的第一个“/”，以方便第二步划分
		path2.substring(1);
		String[] array1=path1.split("/");     //第二步：通过“/”划分绝对路径，并将相同的部分移除
		String[] array2=path2.split("/");
		int len=array1.length<array2.length?array1.length:array2.length;
		
		for(int i=0;i<len;i++){
			if(array1[i].equals(array2[i])){
				path1=path1.substring(path1.indexOf("/")+1);
				path2=path2.substring(path2.indexOf("/")+1);
			}else{
				break;
			}
		}
		System.out.println("不同部分:");
		System.out.println("path1:"+path1);
		System.out.println("path2:"+path2);
		
		
		String[] array3=path1.split("/");     //第三步：对第二步产生的path1进行重新划分，将每一个“XXX/”前面部分换成"。。/"
		for(int i=0;i<array3.length-1;i++){
			result+="../";
		}
		return result+path2;                  //第四步：组装结果
	}
	
	public static void main(String[] args){
		String path1="/qihoo/app/a/b/c/d/new.c";
		String path2="/qihoo/app/1/2/test.c";
		AbsoluteToRelativeLocation convertor=new AbsoluteToRelativeLocation();
		String relativePath=convertor.convert(path1, path2);
		System.out.println("relativePath:"+relativePath);
	}

}

}

#coding:utf-8

a="/qihoo/app/a/b/c/d/new.c"
b="/qihoo/app/1/2/test.c"


def outer(a,b):
    a_list = a.split('/')
    b_list = b.split('/')

    a_max = len(a_list)
    b_max = len(b_list)
    num = min(a_max,b_max)
    path_pre = ''
    for i in range(num):
        if a_list[i] != b_list[i]:
            print path_pre + list2str(b_list[i:])
            break
        else:
            path_pre += '../'

def list2str(temp):
    str_temp = ''
    for index,item in enumerate(temp):
        if index != (len(temp)-1):
            str_temp += item + '/'
        else:
            str_temp += item
    return str_temp


outer(a,b)
            

string path(string &a,string &b){
    string *p=b,*q=b;
    int lena=a.size(a);
    int lenb=b.size(b);
    int count=0;
    for(int i=0;i<lena && i<lenb;i++){
          if(a[i]=='/' &&b[i]=='/'){
              count++;
              q=p+1;
           }
          else if(a[i]!=b[i])
               break;
          p++;
    }
    p="";
    for(int i=1;i<=count;i++)
         p+="../";
   if(p=="")
        p+='/';
    p+=p+q;
    return p;
}

#include<iostream>
#include<string>

using namespace std;

string result = "../";
string&  relativepath(string& str1, string& str2)
{
	int i = 0;
	while (str1[i]==str2[i])
	{
		if (str1[i]=='/')
		{
			result += "../";
		}
		++i;
	}
	result += str2.substr(i);
	return result;
}


int main()
{
	string s1 = "/qihoo/app/a/b/c/d/new.c";
	string s2 = "/qihoo/app/1/2/test.c";
	cout << relativepath(s1, s2) << endl;
	return 0;
}

//大题测试,根据两个文件的绝对路径，输出文件A相对于Ｂ的相对路径
#include<iostream>
#include<string>
#include<vector>
using namespace std;
int main()
{
 vector<char> result;
 string str1,str2;
 cin>>str1;
 cin.clear();
 cin>>str2;
 int i=0;
 while(str1[i]==str2[i])
 {++i;}
 int j=0;
 int count=0;//用来记录字符'/'的个数
 for(;j<=i;++j)//统计'/'的个数
 {
  if(str1[j]=='/')
   count++;
 }
 for(;count>=0;--count)//存储相应个数的‘../’
 {
  result.push_back('.');
  result.push_back('.');
  result.push_back('/');
 }
 for(;i<str2.length();++i)
 {
  result.push_back(str2[i]);
 }
 for(int m=0;m<result.size();m++)
 {
  cout<<result[m];
 }
 cout<<endl;
 system("pause");
 return 0;

}

}

class Solution():
    def Relativedir(self, source, dist):
        #将路径进行分裂
        source = source.split("/")
        dist = dist.split("/")
        print(source,dist)

        len_s = len(source)
        len_d = len(dist)
        #遍历至第一个不同的子路径
        for i in range(min(len_s, len_d)):
            if source[i] != dist[i]:
                break
        print(len_s, len_d, i)
        reladir = []
        #从源文件的路径向上回溯至公共路径的最低一层
        for j in range(i, len_s - 1):
            reladir.append("..")
        #向目的文件遍历
        for j in range(i, len_d):
            reladir.append(dist[j])

        return "/".join(reladir)

so = Solution()
print(so.Relativedir("/qihoo/app/a/b/c/d/new.c", "/qihoo/app/1/2/test.c"))