蓝桥杯2018年第九届真题-全球变暖-题解（C++代码）

解题思路:

注意事项:

参考代码:

#include<iostream>

using namespace std;

const int N = 1010;

char a[N][N];

int d[][2] = { 0 , 1 , 0 , -1 , 1 , 0 , -1 , 0 };

int n;

int ans = 0;

int ans_island = 0;

int flag;

void dfs(int x, int y)

{

if (a[x][y] != '#')

{

return;

}

if (x < 1 || x > n || y < 1 || y > n)

{

return;

}

if (!flag)

{

int cnt = 0;

for (int i = 0; i < 4; i++)

{

int dx = x + d[i][0];

int dy = y + d[i][1];

if (dx > 0 && dx <= n && dy > 0 && dy <= n && a[dx][dy] != '.')

{

cnt++;

}

if (cnt == 4)

{

ans++;

flag = true;

}

}

}

a[x][y] = '*';

for (int i = 0; i < 4; i++)

{

int dx = x + d[i][0];

int dy = y + d[i][1];

if (dx > 0 && dx <= n && dy > 0 && dy <= n && a[dx][dy] != '.')

{

dfs(dx, dy);

}

}

}

int main()

{

cin >> n;

for (int i = 1; i <= n; i++)

{

for (int j = 1; j <= n; j++)

{

cin >> a[i][j];

}

}

for (int i = 1; i <= n; i++)

{

for (int j = 1; j <= n; j++)

{

if (a[i][j] == '#')

{

ans_island++;

flag = false;

dfs(i, j);

}

}

}

cout << ans_island - ans << endl;

return 0;

}