javascript solution, Finds the minimum number of moves required to rearrange the tanks so that each row and each column contains a single tank, and one such shortest sequence of moves

tanks.js

process.stdin.resume();
process.stdin.setEncoding('ascii');

let input_stdin = '';
let input_stdin_array = '';
let input_currentline = 0;

process.stdin.on('data', (data) => {

  input_stdin += data;

});

process.stdin.on('end', () => {

  input_stdin_array = input_stdin.split('\n');
  main();

});

function readLine() {

  return input_stdin_array[input_currentline++];

}

// ///////////// ignore above this line ////////////////////
const resultArray = [];

const pairR = {
  int: 0,
  char: ''
};
const pairC = {
  int: 0,
  char: ''
};

const index = [];

function deployRooks(roworcolumn, numberofRooks, X, Y) {
    
  for (let i = 0; i < numberofRooks; ++i) {

    index[i] = i;
  
}

    // sort
  for (let i = 0; i < numberofRooks; ++i) {

    for (let j = i + 1; j < numberofRooks; ++j) {

      if (roworcolumn[j] < roworcolumn[i]) {

        const tmp = roworcolumn[j];
        roworcolumn[j] = roworcolumn[i];
        roworcolumn[i] = tmp;
        const tmpIndex = index[j];
        index[j] = index[i];
        index[i] = tmpIndex;
      
}
    
}
  
}

    // move up / left
    
      for (let i = 0; i < numberofRooks; ++i) {

    for (; roworcolumn[i] > i; --roworcolumn[i]) {

      pairR.int = index[i] + 1;
      pairR.char = X;
      resultArray.push(pairR);
    
}
  
}
    
    //move down / right
    
      for (let i2 = numberofRooks - 1; i2 >= 0; --i2) {

    for (; roworcolumn[i2] < i2; ++roworcolumn[i2]) {

      pairC.int = index[i2] + 1;
      pairC.char = Y;
      resultArray.push(pairC);
    
}
  
}

    
}

function main() {

    // write your code here.
    // call `readLine()` to read a line.
    // use console.log() to write to stdout

  const a = parseInt(readLine(), 10);
  const rows = [];
  const columns = [];

  for (let i = 0; i < a; ++i) {

    const c = readLine().split(' ');
    rows.push(c[0]);
    columns.push(c[1]);

    --rows[i];
    --columns[i];
  
}

  deployRooks(rows, a, 'Up', 'Down'); // deploys rows
  deployRooks(columns, a, 'Left', 'Right'); // deploy on columns

  //console.log(resultArray);
  console.log(resultArray.length);

}