for loop not working as expected

[raefnal]

This needs to print two columns of numbers, but it just prints the number 11. I'm sure I'm missing something simple, but any help is appreciated.

#include <iostream>
#include <vector>

using namespace std;


int main(){
    vector <int> vec{1, 2, 3};
   int result{};
for (size_t i {0}; i <vec.size(); ++i)
for (size_t j {i+1}; j <vec.size(); ++j)
result = result + vec.at(i) * vec.at(j);
cout <<result;
   cout << endl;
  
    return 0;

}

[keskiverto]

http://www.cplusplus.com/doc/tutorial/control/ writes:

Many of the flow control statements explained in this section require a generic (sub)statement as part of its syntax. This statement may either be a simple C++ statement, -such as a single instruction, terminated with a semicolon (;) - or a compound statement. A compound statement is a group of statements (each of them terminated by its own semicolon), but all grouped together in a block, enclosed in curly braces: {}:

{ statement1; statement2; statement3; }

The entire block is considered a single statement (composed itself of multiple substatements). Whenever a generic statement is part of the syntax of a flow control statement, this can either be a simple statement or a compound statement.

We can add braces around a simple statement; it does not change the code.

#include <iostream>
#include <vector>

using namespace std;

int main(){
   vector <int> vec{1, 2, 3};
   int result{};
   for (size_t i {0}; i <vec.size(); ++i) {
      for (size_t j {i+1}; j <vec.size(); ++j) {
         result = result + vec.at(i) * vec.at(j);
      }
   }
   cout <<result;
   cout << endl;
   return 0;
}

Does this style change clarify the logic that you have written?

[raefnal]

It does...I understand the need for the braces, however, this does not solve what I need to do for this or something close to this to produce two columns of numbers, each first and second number separated by a comma.

[raefnal]

nevermind...i figured it out