In my code, I check for tail coordinates that I store in a dict (the key is in form: 12_-3, so x and y seperated by underscore).

Those coordinates change when the x or y distance with the head is more than abs(1). The code is doing what I want it to do, but I can't match the correct answer, it's actually quite a bit off (it gives me 4720 where I should get 6181).

If anyone sees where my logic is wrong, I would really appreciate the feedback.

https://gist.github.com/Barraka/a000b9447ac87b9ff87464d81b13c4d3

(javascript)

const temp1 = text.split(/\r?\n/);
const headCoordinates={x:0,y:0};
const tailCoordinates={x:0,y:0};
const visited={'0_0':'v'};
let score=1;
let line;

function checkVisited(x,y){
    const coords=`${x}_${y}`;
    if(!visited[coords]) {
        visited[coords]==='v';
        score  ;
    }
}
temp1.forEach( x=> {
    line=x.split('');

    const direction=line[0];
    const distance=parseInt(line[2]);
    if(direction==='L')headCoordinates.x-=distance;
    if(direction==='R')headCoordinates.x =distance;
    if(direction==='U')headCoordinates.y =distance;
    if(direction==='D')headCoordinates.y-=distance;

    //Check seperation
    //Goes right
    while(headCoordinates.x-tailCoordinates.x>1) {
        tailCoordinates.x  ;
        if(headCoordinates.y!==tailCoordinates.y)tailCoordinates.y=headCoordinates.y;
        checkVisited(tailCoordinates.x, tailCoordinates.y);
    }
    //Goes left
    while(headCoordinates.x-tailCoordinates.x<-1) {
        tailCoordinates.x--;
        if(headCoordinates.y!==tailCoordinates.y)tailCoordinates.y=headCoordinates.y;
        checkVisited(tailCoordinates.x, tailCoordinates.y);
    }
    //Goes up
    while(headCoordinates.y-tailCoordinates.y>1) {
        tailCoordinates.y  ;
        if(headCoordinates.x!==tailCoordinates.x)headCoordinates.x=tailCoordinates.x;
        checkVisited(tailCoordinates.x, tailCoordinates.y);
    }
    //Goes down
    while(headCoordinates.y-tailCoordinates.y<-1) {
        tailCoordinates.y--;
        if(headCoordinates.x!==tailCoordinates.x)headCoordinates.x=tailCoordinates.x;
        checkVisited(tailCoordinates.x, tailCoordinates.y);
    }
});

console.log('Score: ', score);

Thanks,