@[W_X_D](/user/768633) **终点可能是障碍** ,故答案为 0 。
你的代码会先判断是不是终点,再判断是不是障碍 。所以如果终点是障碍也会算进去。
by Kevin_Mamba @ 2022-11-04 18:13:00
```cpp
#include <iostream>
using namespace std;
const int N = 15;
int n, m, t, x1, x2, y1, y2;
int g[N][N];
bool st[N][N];
int sum;
void dfs(int x, int y)
{
if(x == x2 && y == y2)
{
sum++;
return;
}
else
{
int dx[4] = {1, 0, -1, 0}, dy[4] = {0, -1, 0, 1};
for(int i = 0; i < 4; i++)
{
if(x >= 1 && x <= n && y >= 1 && y <= m && g[x][y] == 0 && !st[x][y])
{
st[x][y] = true;
dfs(x + dx[i], y + dy[i]);
st[x][y] = false;
}
}
}
}
int main()
{
cin >> n >> m >> t;
cin >> x1 >> y1 >> x2 >> y2;
for(int i = 1; i <= n; i++)
for(int j= 1; j <= m; j++)
g[i][j] = 0;
while(t--)
{
int a, b;
cin >> a >> b;
g[a][b] = 1;
}
if(g[x2][y2]) return puts("0"),0;
dfs(x1, y1);
cout << sum << endl;
return 0;
}
```
by Kevin_Mamba @ 2022-11-04 18:13:59
@[2124Kobe](/user/576934)
感谢大佬的帮助!!
by W_X_D @ 2022-11-04 22:34:21