将自行车分配给人员 - 第一优先级（距离最近的人最近的自行车）

function findBikesForPeople(grid) {

  let row_length = grid.length;
  let col_length = grid[0].length;
  var bikes = [],
    person = [];

  for (var row = 0; row < row_length; row++) {
    for (var col = 0; col < col_length; col++) {
      if (grid[row][col] === 'B') {
        bikes.push([row, col]);
      }
      if (grid[row][col] === 'P') {
        person.push([row, col]);
      }
    }
  }

  var distances = (bikes, person) => {
    var dist = [];
    person.map((single) => {
      var inner = [];
      bikes.map((bike) => {
        inner.push(check_distance(single, bike));
      })
      dist.push(inner);
    })
    return dist;
  }


  //This isn't right
  var AllocateBikes = (distances) => {
    //var result = [];
    //var min = 1;
    //var increment = 0;
    //  let people = distances.length;
    //let bikeCount = distances[0].length;
    //while (people > 0) {
    //  if (Math.min(...distances[]))
    // }
    return distances;
  }

  function check_distance(a, b) {
    return Math.abs(b[1] - a[1]) + Math.abs(b[0] - a[0]);
  }

  let distance_between = distances(bikes, person);
  console.log(AllocateBikes(distance_between));

}
var grid = [
  ['P', '_', 'B', '_', '_'],
  ['_', '_', '_', '_', 'B'],
  ['_', '_', '_', '_', '_'],
  ['_', 'P', '_', '_', '_'],
  ['_', '_', '_', '_', 'B']
];

findBikesForPeople(grid);

function findBikesForPeople(grid) {
    var rows = grid.length, cols = grid[0].length;
    var bikes = [], people = [];
    for (var row = 0; row < rows; row++) {
        for (var col = 0; col < cols; col++) {
            if (grid[row][col] === 'B') {
                bikes.push({y: row, x:col});
            }
            if (grid[row][col] === 'P') {
                people.push({y:row, x:col});
            }
        }
    }
    var combis = [];
    for (var p in people) {
        for (var b in bikes) {
            var d = distance(people[p], bikes[b]);
            combis.push({person:p, bike:b, distance:d});
        }
    }
    combis.sort(function(a,b) {return a.distance - b.distance});
    var hasBike = [], isTaken = [], assignment = [];
    for (var c in combis) {
        var person = combis[c].person, bike = combis[c].bike;
        if (!hasBike[person] && !isTaken[bike]) {
            assignment.push({person:person, 
                             px:people[person].x, py:people[person].y,
                             bike:bike,
                             bx:bikes[bike].x, by:bikes[bike].y});
            hasBike[person] = true;
            isTaken[bike] = true;
        }
    }
    return assignment;

    function distance(a, b) {
        return Math.abs(b.x - a.x) + Math.abs(b.y - a.y);
    }
}

var grid = [['B', '_', 'P', '_', '_', '_'],
            ['_', '_', 'B', '_', '_', '_'],
            ['_', '_', '_', '_', 'B', '_'],
            ['_', '_', '_', '_', '_', '_'],
            ['P', 'B', '_', '_', '_', 'P'],
            ['_', '_', '_', 'P', '_', '_']];
document.write(JSON.stringify(findBikesForPeople(grid)));