• # Questions about "Life Counter" mission

## Question related to mission None

Hi everybody,

I am not sure if the assertions of this mission are correct. The first assertion has only 7 rows, while the picture in the mission shows 8 rows. If I add [0,0,0,0,0,0,0,0] to the initial state then the correct result will appear.

In the second example my algorithm returns 11 and not 15. I don't know why that is. 11 seems correct. Also there seems to be a row missing, too.

In the third example the result should be 4 and not 5. Here are the states: Initial: [0, 1, 0] [0, 0, 1] [1, 1, 1]

After 1st tick: [0, 0, 0] [1, 0, 1] [0, 1, 1]

After 2nd tick: [0, 0, 0] [0, 1, 1] [0, 1, 1]

And from now on nothing will change. So why should there be 5 alive cells after tick 50?

I hope someone can clarify what I am missunderstanding here?!?

Cheers, Hendrik

Here is my code:

```"use strict";
function getLivingNeighbours(tempCells,position){
var sum = 0;
for(var i=Math.max(position[0]-1,0);i<Math.min(position[0]+2,tempCells.length);i++){
for(var j=Math.max(position[1]-1,0);j<Math.min(position[1]+2, tempCells[i].length);j++){
if(i!==position[0] || j!==position[1]){
if(tempCells[i][j]===1){
sum++;
}
}
}
}
return sum;
}

function getLivingCells(cells){
var sum = 0;
for(var i=0;i<cells.length;i++){
for(var j=0;j<cells[i].length;j++){
if(cells[i][j]===1){
sum++;
}
}
}
console.log(sum);
return sum;
}

function copyArray(a){
var b = [];
for(var i=0;i<a.length;i++){
b[i] = [];
for(var j=0;j<a[i].length;j++){
b[i].push(a[i][j]);
}
}
return b;
}

function lifeCounter(cells, n) {
var newCells = [];
for(var nc = 0;nc<cells.length;nc++){
newCells.push([]);
}
for(var s=0;s<n;s++){
for(var i=0;i<cells.length;i++){
for(var j=0;j<cells[i].length;j++){
switch(cells[i][j]){
case 0:
if((getLivingNeighbours(cells,[i,j])===3)){
newCells[i][j]=1;
}else{
newCells[i][j]=0;
}
break;
case 1:
var neighbours = getLivingNeighbours(cells,[i,j]);
if(neighbours<2 || neighbours >3){
newCells[i][j]=0;
}else{
newCells[i][j]=1;
}
break;
}
}
}
cells = copyArray(newCells);
console.log(cells);
}
return getLivingCells(cells);
}

var assert = require('assert');

if (!global.is_checking) {
assert.equal(lifeCounter([[0, 1, 0, 0, 0, 0, 0],
[0, 0, 1, 0, 0, 0, 0],
[1, 1, 1, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 0, 0, 0],
[1, 1, 1, 0, 0, 0, 0]], 15), 14, "Little later");
assert.equal(lifeCounter([[0, 1, 0, 0, 0, 0, 0],
[0, 0, 1, 0, 0, 0, 0],
[1, 1, 1, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 0, 0, 0],
[1, 1, 1, 0, 0, 0, 0]], 4), 15, "Example");
assert.equal(lifeCounter([[0, 1, 0],
[0, 0, 1],
[1, 1, 1]], 50), 5, "Glider");
assert.equal(lifeCounter([[1, 1, 0, 1, 1],
[1, 1, 0, 1, 1],
[0, 0, 0, 0, 0],
[1, 1, 0, 1, 1],
[1, 1, 0, 1, 1]], 100), 16, "Stones");
console.log("Coding complete? Click 'Check' to review your tests and earn cool rewards!");
}
```