Christina Dwyer is searching for a new job. She lives in Shreveport, Louisiana, and has interviews in Barrow, Alaska; Tucson, Arizona; and Rochester, New York. The cost of one-way flights between these four cities is as follows: Shreveport to Barrow costs $855, Shreveport to Tucson costs $803, Shreveport to Rochester costs $113, Barrow to Tucson costs $393, Barrow to Rochester costs $337, and Tucson to Rochester costs $841.

And???

To find the cheapest total cost of all flights for Christina Dwyer's job interviews in Barrow, Tucson, and Rochester, we need to consider various flight combinations.

One way to approach this is by listing all possible flight combinations and adding up their costs. However, this method can be time-consuming for more extensive options.

Another approach, which is more efficient, is to use a technique called the "Traveling Salesman Problem" (TSP). TSP is a classic optimization problem in computer science that seeks the shortest possible path for visiting a set of cities and returning to the starting point.

In this case, we can adapt TSP to find the cheapest route for Christina Dwyer's interviews. Here's how to do it:

1. Create a matrix to represent the costs of traveling between each city. In this case, the cities are Shreveport, Barrow, Tucson, and Rochester, and the matrix will represent the costs between these cities.

| | Shreveport | Barrow | Tucson | Rochester |
|----------|------------|--------|--------|-----------|
| Shreveport| - | 855 | 803 | 113 |
| Barrow | 855 | - | 393 | 337 |
| Tucson | 803 | 393 | - | 841 |
| Rochester| 113 | 337 | 841 | - |

2. We can use algorithmic techniques like the "Branch and Bound" or "Dynamic Programming" methods to solve the TSP and find the cheapest route among all possible combinations.

3. Apply the TSP algorithm to find the minimum cost path that starts in Shreveport, visits all three cities (Barrow, Tucson, and Rochester), and returns to Shreveport. This will give us the cheapest total cost of all flights.

Using this approach, we can find the cheapest total cost for Christina Dwyer's job interviews in Barrow, Tucson, and Rochester. However, manually calculating the TSP for this specific case may be quite complex.

If you have a large number of locations or cities, there are various TSP algorithms and software tools available that can efficiently solve these optimization problems.