Split string that contains delimeter and store into vector pair

[amoureux]

i have been searching for ages on how to split string that is separated by delimeter and storing them into vector pair.

For example, i have a string that contains the following information

"3:4"


and i have the following vector

vector<pair<int, int>> vect.

How do i split the string that is separated by the delimeter and storing each individual data into the vector pair such that the first int contains 3, and the second contain 4.

[helpinghand]

is the format of string always like you have given?

[closed account 3UohqMoL]

Is the delimiter fixed

[amoureux]

yes. the delimeter will always be fixed and the string will always only contain 2 number separated by the delimeter.

[helpinghand]

then you should simply store the value of string before ':' int first int and value after that in the second int (ofcourse after converting them to ints)

[amoureux]

how do i even store the value of string before the delimeter into the int variable. ? i do know how to convert them which is via atoi function.

[helpinghand]

int num1=0,num2=0,flag=0;
vector<pair<int,int> > vect;
for(int i=0;i<s.length();i++){
  if(s[i]==':') flag=1;
  else if(flag==0) num1=num1*10+s[i]-'0';
  else if(flag==1) num2=num2*10+s[i]-'0';
}
vect.push_back({num1,num2});

I think this would work.

[amoureux]

it works. thank you. do you mind if you explain a little bit about your code?

[helpinghand]

check yourself by taking any example and going through the code stepwise: eg, check yourself for the string "234:987", i hope you will get the intuition.

[jlb]

Why not just use a stringstream to process the string?

std::string my_pair{"1234:3323"};
std::stringstream sin(my_pair);
int num1, num2;
char delimiter;
sin >> num1 >> delimiter >> num2;
vect.push_back({num1, num2};

[helpinghand]

This stringstream stuff I have never used. Could you tell me about how it works?

[E0p9LyTq]

An example of how to use a stringstream here at cplusplus:
http://www.cplusplus.com/reference/sstream/stringstream/stringstream/

All you wanted to know about stringstream:
https://en.cppreference.com/w/cpp/io/basic_stringstream

With an example of extracting from a string:
https://en.cppreference.com/w/cpp/io/basic_istream/operator_gtgt