模拟 Codeforces Round #288 (Div. 2) A. Pasha and Pixels

 

题目传送门

 1 /*  2  模拟水题：给定n*m的空白方格，k次涂色，将（x，y）处的涂成黑色，判断第几次能形成2*2的黑色方格，若不能，输出0  3  很挫的判断四个方向是否OK  4 */  5 #include <cstdio>  6 #include <iostream>  7 #include <algorithm>  8 #include <cmath>  9 #include <cstring> 10 #include <map> 11 using namespace std; 12 13 const int MAXN = 1e3 + 10; 14 const int INF = 0x3f3f3f3f; 15 int a[MAXN][MAXN]; 16 17 bool lose(int i, int j, int n, int m) 18 { 19 if (a[i][j] == 1) 20  { 21 if (j < m && a[i][j+1] == 1) 22  { 23 if (i < n && a[i+1][j] == 1) 24  { 25 if (a[i+1][j+1] == 1) 26  { 27 return true; 28  } 29  } 30  } 31 if (j>1 && a[i][j-1] == 1) 32  { 33 if (i < n && a[i+1][j-1] == 1) 34  { 35 if (a[i+1][j] == 1) 36  { 37 return true; 38  } 39  } 40  } 41 if (j > 1 && a[i][j-1] == 1) 42  { 43 if (i > 1 && a[i-1][j-1] == 1) 44  { 45 if (a[i-1][j] == 1) 46  { 47 return true; 48  } 49  } 50  } 51 if (j < m && a[i][j+1] == 1) 52  { 53 if (i > 1 && a[i-1][j] == 1) 54  { 55 if (a[i-1][j+1] == 1) 56  { 57 return true; 58  } 59  } 60  } 61  } 62 63 return false; 64 } 65 66 int main(void) 67 { 68  #ifndef ONLINE_JUDGE 69 freopen ("A.in", "r", stdin); 70 #endif 71 72 int n, m, k; 73 while (~scanf ("%d%d%d", &n, &m, &k)) 74  { 75 memset (a, 0, sizeof (a)); 76 77 bool flag = false; int ans = -1; 78 for (int i=1; i<=k; ++i) 79  { 80 int x, y; 81 scanf ("%d%d", &x, &y); 82 if (a[x][y] == 1) continue; 83 84 a[x][y] = 1; 85 if (lose (x, y, n, m) && !flag) 86  { 87 flag = true; ans = i; 88  } 89  } 90 91 if (!flag) printf ("%d\n", 0); 92 else printf ("%d\n", ans); 93  } 94 95 return 0; 96 }