// 10 minutes

//import SDL;
#include <SDL.h>

int main() {
    SDL_Init(SDL_INIT_VIDEO);

    SDL_Surface* s = SDL_SetVideoMode(640, 480, 32, SDL_SWSURFACE);

    int x1, y1, x2, y2, bx, by, bsx, bsy;
    int i, j;

    int running = 1;

    int winner = 0;

    y2 = y1 = 240;

    bx = 320; by = 240;
    bsx = 5; bsy = 5;


    while (running) {
        SDL_Event e;
        SDL_PumpEvents();

        Uint8* ks = SDL_GetKeyState(0);

        if (ks[SDLK_ESCAPE]) {
            running = 0;
        }

        if (ks[SDLK_UP]) {
            y1 -= 3;
        }
        else if (ks[SDLK_DOWN]) {
            y1 += 3;
        }
        if (ks[SDLK_k]) {
            y2 -= 3;
        }
        else if (ks[SDLK_j]) {
            y2 += 3;
        }

        // MOVE

        bx += bsx;
        by += bsy;

        if (bx < 0) {
            int d = by - y1;
            if (d > 20 || d < -20) {
                running = 0;
                winner = 2;
            }
            else {
                bsx = -bsx;
                bx += bsx;
            }
        }
        if (bx > 640) {
            int d = by - y2;
            if (d > 20 || d < -20) {
                running = 0;
                winner = 1;
            }
            else {
                bsx = -bsx;
                bx += bsx;
            }
        }

        if (by < 0 || by > 480) {
            bsy = -bsy;
            by += bsy;
        }

        // draw

        SDL_Rect r;
        r.w = 640; r.h = 480;
        r.x = 0; r.y = 0;
        SDL_FillRect(s, &r, SDL_MapRGB(s->format, 0, 0, 0));

        r.w = 10; r.h = 40;
        r.x = 0; r.y = y1-20;
        SDL_FillRect(s, &r, SDL_MapRGB(s->format, 255, 255, 255));

        r.w = 10; r.h = 40;
        r.x = 630; r.y = y2-20;
        SDL_FillRect(s, &r, SDL_MapRGB(s->format, 255, 255, 255));

        r.w = 6; r.h = 6;
        r.x = bx-3; r.y = by-3;
        SDL_FillRect(s, &r, SDL_MapRGB(s->format, 255, 255, 255));

        SDL_Flip(s);

        SDL_Delay(16);
    }

    SDL_Quit();

    return 0;
}