我在AVR设备上写了一个战舰游戏。一切正常，只有在游戏地图上放置船只几乎没有问题。有时船只被放在彼此旁边，即使我认为我的代码会阻止它。已经尝试过两天调试它。如果有人能够注意到我错在哪里，可以考虑将place_ships -function的代码放在这里。
int data_map[10][10]; //This has the data of where ships are, where player has shot etc.
char game_map[10][10]; //This is printed in UI. O for miss, X for hit.
int ship_sizes[] = {0,1,2,3,3,4,5};
int ships[] = {0,1,2,3,4,5,6};
void place_ships() { //Places the ships in the game map.
int other_ships; //Variabel for counting if there are already other ships in the area where trying place the ship.
for (i=6; i>0; i--) {
while (1) {
other_ships = 0; //Initialize.
ship_direction = rand() % 10; //Get random ship direction (1-4 = horizontal, 6-10 = vertical)
top_x = (rand() % 8) + 1; //Get random x-coordinate, not from map edges
top_y = (rand() % 8) + 1; //Get random y-coordinate, not from map edges
if (ship_direction < 5) {
if ((top_x-ship_sizes[i]) > -2) { //Make sure that ship has room in game map.
for (j=(top_y-1); j<(top_y+2); j++) { //Following 2 for-loops and if-statement inside makes sure that no other ships are in
//the area where the ship is tried to place.
for (k=(top_x+1); k>(top_x-(ship_sizes[i]-2)); k--) {
if ((data_map[j][k] == 1) || (data_map[j][k] == 2) || (data_map[j][k] == 3) || (data_map[j][k] == 4) || (data_map[j][k] == 5) || (data_map[j][k] == 6)) {
other_ships = 1; //Following 2 'breaks' and 'continue' are there for the situation if
break; //there are other ships in the area, stop placing ship and get new random coordinate and try again.
}
}
if (other_ships == 1) {
break;
}
}
if (other_ships == 1) {
continue;
}
for (l=top_x; l>(top_x-ship_sizes[i]); l--) {
data_map[top_y][l] = ships[i]; //If no other ships in the area, place the ship.
}
loading(); //Wait to optimize harware working. There are known timing issues on AVR. And this
//is here to try to avoid them.
break;
}
}
else if (ship_direction > 5) {
if ((top_y-ship_sizes[i]) > -2) { //Make sure that ship has room in game map.
for (j=(top_y+1); j>(top_y-(ship_sizes[i]-2)); j--) { //Following 2 for-loops and if-statement inside makes sure that no other ships are in
//the area where the ship is tryied toplace.
for (k=(top_x-1); k<(top_x+2); k++) {
if ((data_map[j][k] == 1) || (data_map[j][k] == 2) || (data_map[j][k] == 3) || (data_map[j][k] == 4) || (data_map[j][k] == 5) || (data_map[j][k] == 6)) {
other_ships = 1; //Following 2 'breaks' and 'continue' are there for the situation if
break; //there are other ships in the area, stop placing ship and get new random coordinate and try again.
}
}
if (other_ships == 1) {
break;
}
}
if (other_ships == 1) {
continue;
}
for (l=top_y; l>((top_y-(ship_sizes[i]))); l--) {
data_map[l][top_x] = ships[i]; //If no other ships in the area, place the ship.
}
loading(); //Wait to optimize harware working. There are known timing issues on AVR. And this
//is here to try to avoid them.
break;
}
}
}
}
}
现在原来的问题已经解决了。还有一些船没有放置。什么船舶功能跳过，各不相同。
答案 0 :(得分：1)
您在data_map上执行的查找其他船只的测试正在读取数组的末尾。你应该清理那些循环条件。例如，top_x在被分配(rand() % 8) + 1后可以高达8。然后ship_sizes[i]可以高达5.因此top_x+(ship_sizes[i]+2)可以是15。
我不确定是否可以解决您的问题，但这是一个问题。
您会发现问题出在数组索引中。 C中的数组是0索引的，在某些地方你可以将它们当作1个索引编号。
答案 1 :(得分：1)
在最后一个版本中：
for (k=(top_x+1); k>(top_x-(ship_sizes[i]-2)); k--) {
我认为条件应该是：
k > ( top_x - (ship_sizes[i] + 2) ) // not -2 but + 2
因为我想你要检查船只不会重叠ship_sizes [i]和相邻船只的所有长度。同样适用于y：
top_y-(ship_sizes[i] + 2) // or top_y - ship_sizes[i] - 2
我建议你将这段代码解压缩到函数中，比如CheckOverlap，因为它会简化代码的读取和调试。
此外，从循环中提升条件的估值：
int length = top_x - (ship_sizes[i] + 2);
for (k= top_x+1; k > length; k--) {
更清晰的代码也将是：
int IsPlaced (j,k) {
return 1 <= data_map[j][k] && data_map[j][k] <=6;
}
一般来说，尽量避免代码重复，将所有加倍的功能放在一起。它将减少倍增误差并大大简化您的程序设计，这对您和所有其他读者都有好处。