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
英语真的是差啊，没办法，没理解，好好学英语，这学期过CET4，加油！
遍历搞一下这道题就过了。
1 #include <cstdio>
2 #include <cstring>
3 #include <iostream>
4 #include <algorithm>
5
6 using namespace std;
7 const int max_size = 105;
8
9 int d1[] = {-1, 0, 0, 1};
10 int d2[] = {0, -1, 1, 0};
11
12 bool check(int x, int y, int n)
13 {
14 if(x >= 0 && y >= 0 && x < n && y < n)
15 return true;
16 return false;
17 }
18
19 int main()
20 {
21 int n;
22 int graph[max_size][max_size];
23
24 while(scanf("%d%*c", &n) != EOF)
25 {
26 for(int i = 0; i < n; i++)
27 {
28 for(int j = 0; j < n; j++)
29 {
30 char a = getchar();
31 if(a == ‘o‘)
32 graph[i][j] = 1;
33 else
34 graph[i][j] = 0;
35 }
36 getchar();
37 }
38
39 int tag = false;
40 for(int i = 0; i < n; i++)
41 {
42 for(int j = 0; j < n; j++)
43 {
44 int ans = 0;
45 int x, y;
46 for(int k = 0; k < 4; k ++)
47 {
48 x = i + d1[k];
49 y = j + d2[k];
50 if(check(x, y, n))
51 {
52 if(graph[x][y] == 1)
53 ans++;
54 }
55 }
56 if(ans % 2 != 0)
57 {
58 printf("NO\n");
59 tag = true;
60 break;
61 }
62 }
63 if(tag == true)
64 break;
65 }
66 if(tag == false)
67 printf("YES\n");
68 }
69 return 0;
70 }