C ++:将数组随机放入2D数组中

时间:2011-09-22 04:05:23

标签: c++ arrays multidimensional-array

我正在制作类似战舰的游戏,需要随机将战舰对象放入战斗阵列中。除非我这样做,船只从不放在右下象限(但它们成功放置在其他3个象限中),我不知道为什么。基本上,我得到一个0到地图的长度和高度以及随机方向的随机整数,然后检查船是否适合那里,如果可以,将它放在地图上。但它从未将它们置于右下角。

void BattleMap::placeRandomly(BattleShip& ship) {
bool correct = true; 
int x_start,y_start,dir;
// size_x, size_y denote the length and height of the array respectively
int length = ship.getLength();      
do{
    correct = true; 
    x_start = abs(rand()%(size_x-length));
    if(x_start+length > size_x) x_start -= length;  
    y_start = abs(rand()%(size_y-length));
    if(y_start+length > size_y) y_start -= length;
    dir = rand()%2; // 0 for vertical, 1 for horizontal;
    for ( int i = 0;  i < length;i++) {
        switch(dir){ // Check if there is already a ship in the candidate squares
          case 0:
            if(this->at(x_start,y_start+i)){
              correct = false;
            }
            break;
          case 1:
            if(this->at(x_start+i,y_start)){
              correct = false;
            }
            break;
        }
      }
   }while(!correct);
   // Place the ships into the array
   ....

}

at()功能是:

BattleShip*& BattleMap::at(int x, int y){
    if(x > size_x || y > size_y)return 0; 
// error: invalid initialization of non-const reference of type 'BattleShip*&' from a temporary of type 'int'
    return board[x*size_y +y];
}

1 个答案:

答案 0 :(得分:2)

你正在努力让船离开一边。只需允许x_start和y_start在任何地方:

x_start = rand()%size_x;
y_start = rand()%size_y;

让你的at()函数返回true,如果它偏离一边:

bool BattleMap::at(int x,int y) const
{
  if (x>=size_x || y>=size_y) return true;
  // regular check for a ship at x,y here
}