[es] - C++ Pomoc oko zadatka

Neshonee
Nebojsa Dzinic
radnik,Duel

Član broj: 164701
Poruke: 41
*.dynamic.sbb.rs.

Profil

^{08.07.2011. u 16:37 - pre 155 meseci}

Ljudi imam sad ovaj problem. Treba da iz odredjenog text fajla na osnovu unetog broja iz tog reda ispise neki broj u tom redu koji je uvek na istom mestu.

U Text fajlu imam sledeci text:

Code:

insert into deonica (iddeonica,duzina,Vn,tip_voda,presek,Rd,Ri,Ro,Xd,Xi,Xo,Bd,Bi,Bo,Gd,Gi,Go,pocetak,kraj)
values (4001,1,20,2,null,0.209,0.209,0.75,0.117,0.117,0.112,0.116,0.116,0.695,0,0,0,2001,5001)
insert into deonica (iddeonica,duzina,Vn,tip_voda,presek,Rd,Ri,Ro,Xd,Xi,Xo,Bd,Bi,Bo,Gd,Gi,Go,pocetak,kraj)
values (4002,2,20,2,null,0.209,0.209,0.75,0.117,0.117,0.112,0.116,0.116,0.695,0,0,0,5001,5002)
insert into deonica (iddeonica,duzina,Vn,tip_voda,presek,Rd,Ri,Ro,Xd,Xi,Xo,Bd,Bi,Bo,Gd,Gi,Go,pocetak,kraj)
values (4003,2.5,20,2,null,0.209,0.209,0.75,0.117,0.117,0.112,0.116,0.116,0.695,0,0,0,5002,5007)

Ja na osnovu unete deonice koja ima iddeonica=4001 (znaci unosom broja 4001) treba da ispisem pocetak koji ima vrednost u redu 2001.
Uz pomoc drugara sam uspeo da odradim sledeci kod, mislio sam da znam c++ dok nisam poceo da se bavim malo. Ovde pojedine naredbe ni ne razumem :/

Code:
#include <iostream>
#include <fstream>
#include <map>
#include <sstream>

int main(int argc, char* argv[]) {
if (argc != 2) {
std::cerr << "Usage: test [inputfile]" << std::endl;
return 1;
}
std::fstream stream(argv[1]);
if (!stream.good()) {
std::cerr << "Error: could not open file: " << argv[1] << std::endl;
return 2;
}
std::string line;
std::map<int, std::string> map;
while (std::getline(stream, line)) {
std::string::size_type pos = line.find(',');
std::stringstream sstream(line.substr(0, pos));
int index;
sstream >> index;
map[index] = line.substr(pos+2);
}
int in;
while (std::cin >> in) {
std::map<int, std::string>::iterator i = map.find(in);
if (i == map.end())
std::cerr << "index not found" << std::endl;
else
std::cout << i->second << std::endl;
}
return 0;
}

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