vector data not adding in while loop - c++

Question

I am trying to add the elements of a vector of doubles (belonging to a class called path) into a double called dist using a for loop twice. I want it to add all the distances inside the class vector for the first iteration and then at the end set the double dist back to zero and add them up again. However, when I run it, it works fine the first time as it prints out the correct answer of 3, but the double ends up being 0 by the time it prints out the second time and after the loop is done. It looks like it is not adding the vector's data. Why is this happening? Thanks for any help
class Path
{
public:
vector<double> distance;
vector<double> safety;
};
int main()
{
int i = 0;
int k = 0;
vector<Path*> paths;
Path* paths.at(0) = new Path;
Path* paths.at(1) = new Path;
paths.at(0)->distance.push_back(1.0);
paths.at(0)->distance.push_back(2.0);
paths.at(1)->distance.push_back(1.0);
paths.at(1)->distance.push_back(2.0)
double dist = 0;
for(k = 0; k < paths.size(); k++)
{
for(i = 0; i< paths.at(k)->distance.size(); i++)
{
dist += paths.at(i)->distance.at(i);
}
cout << dist << endl;
dist = 0;
}
delete paths.at(0); delete paths.at(1);
return 0;
}

Answer 1

This line has a bug:
dist += paths.at(i)->distance.at(i);
Should be:
dist += paths.at(k)->distance.at(i);

Answer 2

for(k = 0; k < route -> distance.size(); k++)
{
for(i = 0; i< route->distance.size(); i++)
{
dist += route->distance.at(i);
}
cout << dist << endl;
dist = 0;
}
This will give you k outputs (that is, it will iterator over the vector k times). If you just want to iterate over the vector twice, then this is not how you want to write your loops. Instead, you'll want 2 separate (not nested) loops:
for (int i = 0; i < route->distance.size(); ++i)
{
dist += route->distance[i];
}
cout << dist << endl;
dist = 0;
for (int k = 0; k < route->distance.size(); ++k)
{
dist += route->distance[k];
}
cout << dist << endl;
Or you could use a function that would do that for you:
dist = std::accumulate(route->distance.begin(), route->distance.end(), 0);
Edit
With your update, you now have invalid operations:
vector<Path*> paths;
Path* paths.at(0) = new Path; // at(0) does not exist! exception will be thrown
Path* paths.at(1) = new Path; // same here

Answer 3

It's C++, use its power:
#include <numeric>
#include <vector>
#include <iostream>
struct Path
{
std::vector<double> distance;
std::vector<double> safety;
};
int main()
{
std::vector<Path> paths{
{
{ 1.0, 2.0 }, {}
},
{
{ 3.0 }, {}
}
};
// loop version
double sum = 0.0;
for ( auto const& path : paths ) {
for ( double d : path.distance ) {
sum += d;
}
}
std::cout << sum << std::endl;
// ...
algorithm version
std::cout <<
std::accumulate(
paths.begin(),
paths.end(),
0,
[](double res, Path const& path) {
return res + std::accumulate(
path.distance.begin(),
path.distance.end(),
0);
})
<<std::endl;
}
-> Ideone
use RAII
use algorithms range-based loops if you insist on loops
don't forget software design