Problem Description
A while ago I had trouble sleeping. I used to lie awake, staring at the ceiling, for hours and hours. Then one day my grandmother suggested I tried counting sheep after I'd gone to bed. As always when my grandmother suggests things, I decided to try it out. The only problem was, there were no sheep around to be counted when I went to bed.
Creative as I am, that wasn't going to stop me. I sat down and wrote a computer program that made a grid of characters, where # represents a sheep, while . is grass (or whatever you like, just not sheep). To make the counting a little more interesting, I also decided I wanted to count flocks of sheep instead of single sheep. Two sheep are in the same flock if they share a common side (up, down, right or left). Also, if sheep A is in the same flock as sheep B, and sheep B is in the same flock as sheep C, then sheeps A and C are in the same flock.
Now, I've got a new problem. Though counting these sheep actually helps me fall asleep, I find that it is extremely boring. To solve this, I've decided I need another computer program that does the counting for me. Then I'll be able to just start both these programs before I go to bed, and I'll sleep tight until the morning without any disturbances. I need you to write this program for me.
Creative as I am, that wasn't going to stop me. I sat down and wrote a computer program that made a grid of characters, where # represents a sheep, while . is grass (or whatever you like, just not sheep). To make the counting a little more interesting, I also decided I wanted to count flocks of sheep instead of single sheep. Two sheep are in the same flock if they share a common side (up, down, right or left). Also, if sheep A is in the same flock as sheep B, and sheep B is in the same flock as sheep C, then sheeps A and C are in the same flock.
Now, I've got a new problem. Though counting these sheep actually helps me fall asleep, I find that it is extremely boring. To solve this, I've decided I need another computer program that does the counting for me. Then I'll be able to just start both these programs before I go to bed, and I'll sleep tight until the morning without any disturbances. I need you to write this program for me.
Input
The first line of input contains a single number T, the number of test cases to follow.
Each test case begins with a line containing two numbers, H and W, the height and width of the sheep grid. Then follows H lines, each containing W characters (either # or .), describing that part of the grid.
Each test case begins with a line containing two numbers, H and W, the height and width of the sheep grid. Then follows H lines, each containing W characters (either # or .), describing that part of the grid.
Output
For each test case, output a line containing a single number, the amount of sheep flock son that grid according to the rules stated in the problem description.
Notes and Constraints
0 < T <= 100
0 < H,W <= 100
Notes and Constraints
0 < T <= 100
0 < H,W <= 100
Sample Input
2
4 4
#.#.
.#.#
#.##
.#.#
3 5
###
.#.
.#.
.#.
###
Sample Output
6 3
题解：题目描述什么的一大段废话，直接看输入输出，发现是一个经典的DFS连通块问题。
#include <cstdio> #include <iostream> #include <string> #include <sstream> #include <cstring> #include <stack> #include <queue> #include <algorithm> #include <cmath> #include <map> #define ms(a) memset(a,0,sizeof(a)) #define msp memset(mp,0,sizeof(mp)) #define msv memset(vis,0,sizeof(vis)) using namespace std; //#define LOCAL char mp[120][120]; int n,m; int ans; int dir[4][2]={{0,1},{0,-1},{1,0},{-1,0}}; void dfs(int x,int y) { for(int i=0;i<4;i++) { int nx=x+dir[i][0],ny=y+dir[i][1]; if(nx>=0&&nx<n&&ny>=0&&ny<m) { if(mp[nx][ny]=='#') { mp[nx][ny]='.'; dfs(nx,ny); } } } return; } int main() { #ifdef LOCAL freopen("in.txt", "r", stdin); #endif // LOCAL //Start int N; cin>>N; while(N--) { cin>>n>>m; msp,ans=0; for(int i=0; i<n; i++)cin>>mp[i]; for(int i=0; i<n; i++) for(int j=0; j<m; j++) if(mp[i][j]=='#') { mp[i][j]='.'; ans++; dfs(i,j); } printf("%d ",ans); } return 0; }