seatsInTheater.js

/*
Your friend advised you to see a new performance in the most popular theater in the city. He knows a lot about art and his advice is usually good, but not this time: the performance turned out to be awfully dull. It's so bad you want to sneak out, which is quite simple, especially since the exit is located right behind your row to the left. All you need to do is climb over your seat and make your way to the exit.

The main problem is your shyness: you're afraid that you'll end up blocking the view (even if only for a couple of seconds) of all the people who sit behind you and in your column or the columns to your left. To gain some courage, you decide to calculate the number of such people and see if you can possibly make it to the exit without disturbing too many people.

Given the total number of rows and columns in the theater (nRows and nCols, respectively), and the row and column you're sitting in, return the number of people who sit strictly behind you and in your column or to the left, assuming all seats are occupied.

Example

For nCols = 16, nRows = 11, col = 5, and row = 3, the output should be
seatsInTheater(nCols, nRows, col, row) = 96.

Here is what the theater looks like:


Input/Output

[execution time limit] 4 seconds (js)

[input] integer nCols

An integer, the number of theater's columns.

Guaranteed constraints:
1 ≤ nCols ≤ 1000.

[input] integer nRows

An integer, the number of theater's rows.

Guaranteed constraints:
1 ≤ nRows ≤ 1000.

[input] integer col

An integer, the column number of your own seat (1-based).

Guaranteed constraints:
1 ≤ col ≤ nCols.

[input] integer row

An integer, the row number of your own seat (1-based).

Guaranteed constraints:
1 ≤ row ≤ nRows.

[output] integer

The number of people who sit strictly behind you and in your column or to the left.
*/

// Solution :

function seatsInTheater(nCols, nRows, col, row) {
  // Calculate area/total seats in theater
  let totalSeats = nCols * nRows;
  
  /* Calculate cols and rows behind my seat
     Add one to col because my people behind me in my col are  counted
  */
  let newColNumber = nCols - col + 1;
  let newRowNumber = nRows - row;
  
  // Calculate area of seats behind me
  let peopleBehindMe = newColNumber * newRowNumber;
  
  return peopleBehindMe;
}