TRON: Game A.I algorithm?

Question

Lightcycles or whatever it was called like.

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Given a 2d array representing the game map, where each element can be either 0 or 1 (0 representing blank space and 1 representing filled space), what is the algorithm used for TRON enemy A.I?

Answer 1

I haven't had the chance to dig through their code, but Armagetron Advanced is an open-source relatively mature lightcycle battling game.

You can find the source (and executables) here: http://armagetronad.net/downloads.php

Answer 2

This was the subject of one of the Google Ai competitions

There are some great resources from that page:

• http://csclub.uwaterloo.ca/contest/xiao_strategy.php

• http://www.sifflez.org/misc/tronbot/index.html

Answer 3

i don't know of any algorithms but i can create a simple "algorithm" in java

//2D boolean (true/false) array
boolean map[][] = new boolean[20][20];
//this represents the position of the AI on the map
int x = 10, y = 10;
//this int will be 1 - 4 and will represent a direction
//1 - up
//2 - right
//3 - down
//4 - left
int direction = 1;

void init(int startX, int startY){
    //set the x and y to a starting position
    x = startX;
    y = startY;
    //this will set the entire array to false
    int i = 0, j = 0;
    while (i<20){
        while(j<20){
            map[i][j] = false;
            j++;
        }
        j = 0;
        i++;
    }

    //and this will set the starting position to true
    map[x][y] = true;
}

void tick(){
    try{
        //try to go straight and will error if 
        //it cannot because it would be out of bounds
        switch(direction){
        case 1: //up
            if(!map[x][y-1]){ //will error out here if the block in front is out of bounds
                map[x][y-1] = true;
                y--;
            }
            return;
        case 2: //right
            if(!map[x+1][y]){ //will error out here if the block in front is out of bounds
                map[x+1][y] = true;
                x++;
            }
            return;
        case 3: //down
            if(!map[x][y+1]){ //will error out here if the block in front is out of bounds
                map[x][y+1] = true;
                y++;
            }
            return;
        case 4: //left
            if(!map[x-1][y]){ //will error out here if the block in front is out of bounds
                map[x-1][y] = true;
                x--;
            }
            return;
        }
    }catch(Exception e){

    }
    //this next bit will only be  triggered if the AI could not go straight

    //define two temporary variables, fairly self explanatory.
    boolean canGoLeft = false, canGoRight = false;

    //defines whether it is safe to go left
    //turn left respectively
    //test if straight is safe
    direction--;
    try{
        //try to go straight and will error if 
        //it cannot because it would be out of bounds
        switch(direction){
        case 1: //up
            if(!map[x][y-1]){ //will error out here if the block in front is out of bounds
                canGoLeft = true;
            }else canGoLeft = false;
            break;
        case 2: //right
            if(!map[x+1][y]){ //will error out here if the block in front is out of bounds
                canGoLeft = true;
            }else canGoLeft = false;
            break;
        case 3: //down
            if(!map[x][y+1]){ //will error out here if the block in front is out of bounds
                canGoLeft = true;
            }else canGoLeft = false;
            break;
        case 4: //left
            if(!map[x-1][y]){ //will error out here if the block in front is out of bounds
                canGoLeft = true;
            }else canGoLeft = false;
            break;
        }
    }catch(Exception e){
        canGoLeft = false;
    }
    //return to original direction before test
    direction++;

    //now perform the same test but with turning right
    //turn right respectively
    direction++;
    try{
        //try to go straight and will error if 
        //it cannot because it would be out of bounds
        switch(direction){
        case 1: //up
            if(!map[x][y-1]){ //will error out here if the block in front is out of bounds
                canGoRight = true;
            }else canGoRight = false;
            break;
        case 2: //right
            if(!map[x+1][y]){ //will error out here if the block in front is out of bounds
                canGoRight = true;
            }else canGoRight = false;
            break;
        case 3: //down
            if(!map[x][y+1]){ //will error out here if the block in front is out of bounds
                canGoRight = true;
            }else canGoRight = false;
            break;
        case 4: //left
            if(!map[x-1][y]){ //will error out here if the block in front is out of bounds
                canGoRight = true;
            }else canGoRight = false;
            break;
        }
    }catch(Exception e){
        canGoRight = false;
    }
    direction--;

    if(canGoLeft&&!canGoRight){//can only go left
        direction--;
        try{
            //try to go straight and will error if 
            //it cannot because it would be out of bounds
            switch(direction){
            case 1: //up
                if(!map[x][y-1]){ //will error out here if the block in front is out of bounds
                    map[x][y-1] = true;
                    y--;
                }
                return;
            case 2: //right
                if(!map[x+1][y]){ //will error out here if the block in front is out of bounds
                    map[x+1][y] = true;
                    x++;
                }
                return;
            case 3: //down
                if(!map[x][y+1]){ //will error out here if the block in front is out of bounds
                    map[x][y+1] = true;
                    y++;
                }
                return;
            case 4: //left
                if(!map[x-1][y]){ //will error out here if the block in front is out of bounds
                    map[x-1][y] = true;
                    x--;
                }
                return;
            }
        }catch(Exception e){

        }
    }else if(!canGoLeft&&canGoRight){//can only go right
        direction++;
        try{
            //try to go straight and will error if 
            //it cannot because it would be out of bounds
            switch(direction){
            case 1: //up
                if(!map[x][y-1]){ //will error out here if the block in front is out of bounds
                    map[x][y-1] = true;
                    y--;
                }
                return;
            case 2: //right
                if(!map[x+1][y]){ //will error out here if the block in front is out of bounds
                    map[x+1][y] = true;
                    x++;
                }
                return;
            case 3: //down
                if(!map[x][y+1]){ //will error out here if the block in front is out of bounds
                    map[x][y+1] = true;
                    y++;
                }
                return;
            case 4: //left
                if(!map[x-1][y]){ //will error out here if the block in front is out of bounds
                    map[x-1][y] = true;
                    x--;
                }
                return;
            }
        }catch(Exception e){

        }
    }else if(canGoLeft&&canGoRight){//can go either way so it will pick randomly
        if(System.currentTimeMillis()%2==0){//random, will be true half of the time and false the other half
            //change direction one anticlockwise
            direction--;
            try{
                //try to go straight and will error if 
                //it cannot because it would be out of bounds
                switch(direction){
                case 1: //up
                    if(!map[x][y-1]){ //will error out here if the block in front is out of bounds
                        map[x][y-1] = true;
                        y--;
                    }
                    return;
                case 2: //right
                    if(!map[x+1][y]){ //will error out here if the block in front is out of bounds
                        map[x+1][y] = true;
                        x++;
                    }
                    return;
                case 3: //down
                    if(!map[x][y+1]){ //will error out here if the block in front is out of bounds
                        map[x][y+1] = true;
                        y++;
                    }
                    return;
                case 4: //left
                    if(!map[x-1][y]){ //will error out here if the block in front is out of bounds
                        map[x-1][y] = true;
                        x--;
                    }
                    return;
                }
            }catch(Exception e){

            }
        }else{
            //change direction one clockwise
            direction++;
            try{
                //try to go straight and will error if 
                //it cannot because it would be out of bounds
                switch(direction){
                case 1: //up
                    if(!map[x][y-1]){ //will error out here if the block in front is out of bounds
                        map[x][y-1] = true;
                        y--;
                    }
                    return;
                case 2: //right
                    if(!map[x+1][y]){ //will error out here if the block in front is out of bounds
                        map[x+1][y] = true;
                        x++;
                    }
                    return;
                case 3: //down
                    if(!map[x][y+1]){ //will error out here if the block in front is out of bounds
                        map[x][y+1] = true;
                        y++;
                    }
                    return;
                case 4: //left
                    if(!map[x-1][y]){ //will error out here if the block in front is out of bounds
                        map[x-1][y] = true;
                        x--;
                    }
                    return;
                }
            }catch(Exception e){

            }
        }
    }
}