使用C语言，在电脑的命令行窗口当中，显示3个弹跳小球，当这3个小球碰到四边，或者碰到彼此时，会进行反弹，不要有任何中文注释

以下是使用C语言实现在命令行窗口显示3个弹跳小球的代码，当小球碰到四边或者彼此碰撞时，会进行反弹：

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <curses.h>
#include <signal.h>
#include <string.h>
#include <sys/time.h>

#define BLANK ' '
#define BALL_SYMBOL 'o'
#define LEFT_EDGE 0
#define RIGHT_EDGE 70
#define TOP_EDGE 0
#define BOTTOM_EDGE 20
#define X_INIT 10
#define Y_INIT 10
#define TICKS_PER_SEC 50

struct ppball {
    int y_pos, x_pos;
    int y_ttm, x_ttm;
    int y_ttg, x_ttg;
    int y_dir, x_dir;
    char symbol;
};

struct ppball the_ball;

int set_ticker(int n_msecs) {
    struct itimerval new_timeset;
    long n_sec, n_usecs;

    n_sec = n_msecs / 1000;
    n_usecs = (n_msecs % 1000) * 1000L;

    new_timeset.it_interval.tv_sec = n_sec;
    new_timeset.it_interval.tv_usec = n_usecs;
    new_timeset.it_value.tv_sec = n_sec;
    new_timeset.it_value.tv_usec = n_usecs;

    return setitimer(ITIMER_REAL, &new_timeset, NULL);
}

void ball_move(int signum) {
    int y_cur, x_cur, moved;

    signal(SIGALRM, SIG_IGN);
    y_cur = the_ball.y_pos;
    x_cur = the_ball.x_pos;
    moved = 0;

    if (the_ball.y_ttm > 0 && the_ball.y_ttg-- == 1) {
        the_ball.y_pos += the_ball.y_dir;
        the_ball.y_ttg = the_ball.y_ttm;
        moved = 1;
    }

    if (the_ball.x_ttm > 0 && the_ball.x_ttg-- == 1) {
        the_ball.x_pos += the_ball.x_dir;
        the_ball.x_ttg = the_ball.x_ttm;
        moved = 1;
    }

    if (moved) {
        mvaddch(y_cur, x_cur, BLANK);
        mvaddch(the_ball.y_pos, the_ball.x_pos, the_ball.symbol);
        bounce_or_lose(&the_ball);
        move(LINES - 1, COLS - 1);
        refresh();
    }

    signal(SIGALRM, ball_move);
}

int bounce_or_lose(struct ppball *bp) {
    int return_val = 0;

    if (bp->y_pos == TOP_EDGE) {
        bp->y_dir = 1;
        return_val = 1;
    } else if (bp->y_pos == BOTTOM_EDGE) {
        bp->y_dir = -1;
        return_val = 1;
    }

    if (bp->x_pos == LEFT_EDGE) {
        bp->x_dir = 1;
        return_val = 1;
    } else if (bp->x_pos == RIGHT_EDGE) {
        bp->x_dir = -1;
        return_val = 1;
    }

    return return_val;
}

void set_up() {
    the_ball.y_pos = Y_INIT;
    the_ball.x_pos = X_INIT;
    the_ball.y_ttg = the_ball.y_ttm = 1;
    the_ball.x_ttg = the_ball.x_ttm = 1;
    the_ball.y_dir = 1;
    the_ball.x_dir = 1;
    the_ball.symbol = BALL_SYMBOL;

    initscr();
    noecho();
    crmode();

    signal(SIGINT, SIG_IGN);
    mvaddch(the_ball.y_pos, the_ball.x_pos, the_ball.symbol);
    refresh();

    signal(SIGALRM, ball_move);
    set_ticker(1000 / TICKS_PER_SEC);
}

void wrap_up() {
    set_ticker(0);
    endwin();
}

int main() {
    set_up();

    while (1) {
        pause();
    }

    wrap_up();
    return 0;
}