sysrap/tests/LongestCommonPrefixTest.cc

0001 // name=LongestCommonPrefixTest ; gcc $name.cc -std=c++11 -lstdc++ -o /tmp/$name && /tmp/$name
0002
0003 #include <algorithm>
0004 #include <iostream>
0005 #include <vector>
0006 #include <string>
0007
0008 /**
0009 translation from the python os.path.commonprefix
0010 **/
0011
0012 std::string commonprefix(const std::vector<std::string>& a)
0013 {
0014     std::vector<std::string> aa(a);
0015     std::sort( aa.begin(), aa.end() );
0016     const std::string& s1 = aa[0] ;
0017     const std::string& s2 = aa[aa.size()-1] ;
0018     for(unsigned i=0 ; i < s1.size() ; i++) if( s1[i] != s2[i] ) return s1.substr(0,i) ;
0019     return s1 ;
0020 }
0021
0022 void dump(const std::vector<std::string>& a)
0023 {
0024     std::cout << "-----" << std::endl ;
0025     for(unsigned i=0 ; i < a.size() ; i++ ) std::cout << a[i] << std::endl;
0026 }
0027
0028
0029 int main()
0030 {
0031     std::vector<std::string> a = { "one/z", "one/a", "one/b", "one/c" } ;
0032     dump(a);
0033
0034     std::string cpfx = commonprefix(a);
0035     std::cout << " cpfx " << cpfx << std::endl ;
0036
0037     dump(a);
0038
0039
0040     return 0 ;
0041 }