To find the front line of Invaders for my space invaders game, I had to find the lowest coordinate of each invader in each column.

I brute-forced it.

Here is my code:

getFrontLine = () => {
//I need to find the row of aliens that's unimpeded.
let allInvaderCopy = this.state.allInvaders
let invaders = this.state.invaderCoordinates
//if I reverse the list, and then iterate through it, the first eleven that aren't dead should be the front line.
//if one gets shot though, that alters things. So I need to keep iterating and checking against the previous row.
//So what I need to do is reverse the whole array, then break it into increments of 11, and then check them against each other.
let firstRow = [];
let secondRow = [];
let thirdRow = [];
let fourthRow = [];
let fifthRow = [];
for (let i = 0; i < 11; i++){
firstRow.push(allInvaderCopy[i]);
secondRow.push(allInvaderCopy[i + 11]);
thirdRow.push(allInvaderCopy[i + 22]);
fourthRow.push(allInvaderCopy[i + 33]);
fifthRow.push(allInvaderCopy[i + 44]);
}
let i = 0;
let frontLine = [];
while (i < 11){
if (this.checkIfDead(firstRow, i) === undefined){
let newInvader = invaders.find(invader => invader.id === (firstRow[i].id));
frontLine.push(newInvader);
i++;
} else if (this.checkIfDead(firstRow, i) !== undefined){
if (this.checkIfDead(secondRow, i) === undefined){
let newInvader = invaders.find(invader => invader.id === (secondRow[i].id));
frontLine.push(newInvader);
i++;
} else if (this.checkIfDead(secondRow, i) !== undefined){
if (this.checkIfDead(thirdRow, i) === undefined){
let newInvader = invaders.find(invader => invader.id === (thirdRow[i].id));
frontLine.push(newInvader);
i++;
} else if (this.checkIfDead(thirdRow, i) !== undefined){
if (this.checkIfDead(fourthRow, i) === undefined){
let newInvader = invaders.find(invader => invader.id === (fourthRow[i].id));
frontLine.push(newInvader);
i++;
} else if (this.checkIfDead(fourthRow, i) !== undefined){
if (this.checkIfDead(fifthRow, i) === undefined){
let newInvader = invaders.find(invader => invader.id === (fifthRow[i].id));
frontLine.push(newInvader);
i++;
} else if (this.checkIfDead(fifthRow, i) !== undefined){
i++;
}
}
}
}
}
}
return frontLine;
}

The code is ugly. Even uglier on medium, which apparently doesn’t carry indentations over. But it runs, and it works.