output

[arunix]

hello
here is code from "The C++ Programming langauge" by Bjarne Stroustrup.
the code is working but not showing the output when press ctrl+c it
shows only interrupt and first input.
wht's wrong with this code.
thnaks .
here is the code


#include<iostream>
#include<string>
#include<vector>

using namespace std;

struct Pair{ string name; double val;};
vector<Pair> pairs;
double& value(const string& s)
{
for(unsigned int i=0; i < pairs.size(); i++)
if(s==pairs.name) return pairs.val;
Pair p={s,0};
pairs.push_back(p);
return pairs[pairs.size()-1].val;
}

int main()
{
string buf;
while(cin>>buf) value(buf)++;
for(vector<Pair> :: const_iterator p= pairs.begin(); p != pairs.end
();++p)
cout <<p->name << " : "<<p->val <<"\n";

return 0;
}

 

[arunix]

Thanks Sam for reply..
but again its not working
it shows like this.
for complie i use this command......

~/data/CPP/SSC++ $ g++ -Wall -Wextra -ansi -pedantic ex-5-4-1.cpp
~/data/CPP/SSC++ $ ./a.out
aa
bb
aa
bb
aa
aa
bb // press Ctrl+D
interrupt
is there something wrong
and i am confused with


while(cin>>buf) value(buf)++;
why increment ?

..........

 

[domachine]

Thanks Sam for reply..
but again its not working
it shows like this.
for complie i use this command......

~/data/CPP/SSC++ $ g++ -Wall -Wextra -ansi -pedantic  ex-5-4-1.cpp
~/data/CPP/SSC++ $ ./a.out
aa
bb
aa
bb
aa
aa
bb      // press Ctrl+D
interrupt
is there something wrong
and i am confused with

while(cin>>buf) value(buf)++;
why increment ?

.........

I think you should first understand some basic things of C/C++ before
moving on to topics like vector etc.
The question "why increment ?" tells me that you're a beginner. So
move on slowly.
Start your book from the beginning and try again.

Greetings

 

[Jonathan Lee]

for complie i use this command......
~/data/CPP/SSC++ $ g++ -Wall -Wextra -ansi -pedantic  ex-5-4-1.cpp

That seems ok. Worked for me.

aa
bb
aa
bb
aa
aa
bb      // press Ctrl+D
interrupt

Do you mean that you don't get the list of frequencies at
the end? i.e.,
aa: 4
bb: 3

That seems odd... but I would think it has less to do with
your program than your OS, or the particular terminal
application you're using.

and i am confused with

while(cin>>buf) value(buf)++;
why increment ?

It's counting the number of times each input string is
typed. "value()" returns a reference to "number of times
'buf' has been typed". Then that number is incremented.

--Jonathan

 

[arunix]

I think you should first understand some basic things of C/C++ before
moving on to topics like vector etc.
The question "why increment ?" tells me that you're a beginner. So
move on slowly.
Start your book from the beginning and try again.

Greetings

yes i did it....

 

[arunix]

Do you mean that you don't get the list of frequencies at
the end? i.e.,
aa: 4
bb: 3
yes

That seems odd... but I would think it has less to do with
your program than your OS, or the particular terminal
application you're using.

using gcc 4.4.2

It's counting the number of times each input string is
typed. "value()" returns a reference to "number of times
'buf' has been typed". Then that number is incremented.

Thanks...

 

[James Kanze]

arunix writes:

There's nothing wrong with it. Press CTRL-D instead of CTRL-C.

Or some other system specific sequence. (Under Windows, it's
CTRL-Z.) Fundamentally, end of file doesn't exist for a
keyboard: Unix sort of simulates it if you enter CTRL-D at the
beginning of the line (supposing no ones been playing around
with stty); traditionally, Windows library software considers
CTRL-Z an end of file in any text file.

And both agree about CTRL-C: terminate the program doing the
input, or all programs in the "terminal group" under Unix. (But
the program can catch the signal, and not die, and of course, if
you've let someone else get at your terminal while you're logged
in, and they've played around with stty, who knows what may
happen.)