A. Appleman and Easy Task
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output
Toastman came up with a very easy task. He gives it to Appleman, but Appleman doesn‘t know how to solve it. Can you help him?
Given a n × n checkerboard. Each cell of the board has either character ‘x‘, or character ‘o‘. Is it true that each cell of the board has even number of adjacent cells with ‘o‘? Two cells of the board are adjacent if they share a side.
Input
The first line contains an integer n (1 ≤ n ≤ 100). Then n lines follow containing the description of the checkerboard. Each of them contains n characters (either ‘x‘ or ‘o‘) without spaces.
Output
Print "YES" or "NO" (without the quotes) depending on the answer to the problem.
Sample test(s)
input
3xxoxoxoxx
output
YES
input
4xxxoxoxooxoxxxxx
output
NO 解题：暴力枚举即可。
1 #include <iostream>
2 #include <cstdio>
3 #include <cstring>
4 #include <cmath>
5 #include <algorithm>
6 #include <climits>
7 #include <vector>
8 #include <queue>
9 #include <cstdlib>
10 #include <string>
11 #include <set>
12 #include <stack>
13 #define LL long long
14 #define pii pair<int,int>
15 #define INF 0x3f3f3f3f
16 using namespace std;
17 const int maxn = 110;
18 int n;
19 char mp[maxn][maxn];
20 const int dir[4][2] = {0,-1,0,1,-1,0,1,0};
21 int main() {
22 int ans;
23 bool flag;
24 while(~scanf("%d",&n)){
25 getchar();
26 memset(mp,‘x‘,sizeof(mp));
27 for(int i = 1; i <= n; i++){
28 for(int j = 1; j <= n; j++)
29 mp[i][j] = getchar();
30 getchar();
31 }
32 flag = true;
33 for(int i = 1; i <= n; i++){
34 for(int j = 1; j <= n; j++){
35 ans = 0;
36 for(int k = 0; k < 4; k++){
37 int x = i+dir[k][0];
38 int y = j+dir[k][1];
39 if(mp[x][y] == ‘o‘) ans++;
40 }
41 if(ans&1) {flag = false;break;}
42 }
43 }
44 flag?puts("YES"):puts("NO");
45 }
46 return 0;
47 }