最大正方形

 1 // ConsoleApplication4.cpp : 定义控制台应用程序的入口点。
 2 //
 3 #include "stdafx.h"
 4 #include <iostream>
 5 #include <string>
 6 
 7 
 8 using namespace std;
 9 
10 int N = 4;
11 int M = 4;
12 int a[4][4] = { {0, 0, 0, 0}, 13                 {1, 1, 1, 1}, 14                 {1, 1, 1, 1}, 15                 {0, 1, 1, 1} };
16 
17 
18 int max = 0;
19 int L = 0;
20 
21 
22 int main(void)
23 {
24     for (int i = 0; i < N; ++i)
25     {
26         for (int j = 0; j < M; ++j)
27         {
28             L = 0;
29             for (int n = i; n < N; ++n)
30             {
31                 if (n - i>L)
32                 {
33                     break;
34                 }
35                 for (int m = j; m < M; ++m)
36                 {
37                     if (a[n][m] == 0)
38                     {
39                         if (m == j)
40                         {
41                             int temp = ((n - i )>(m - j)) ? (m - j) : (n - i);
42                             L = ((n - i)>(m - j)) ? (n - i) : (m - j);
43                             if (temp>max)
44                                 max = temp;
45                             break;
46                         }
47                         else
48                         {
49                             int temp = ((n - i + 1)>(m - j)) ? (m - j) : (n - i + 1);
50                             L = ((n - i + 1) > (m - j)) ? (n - i + 1) : (m - j);
51                             if (temp>max)
52                                 max = temp;
53                             break;
54                         }
55 
56                     }
57                     else if (m == M - 1)
58                     {
59                         int temp = ((n - i + 1) > (m - j + 1)) ? (m - j + 1) : (n - i + 1);
60                         L = ((n - i + 1) > (m - j + 1)) ? (n - i + 1) : (m - j + 1);
61                         if (temp>max)
62                             max = temp;
63                         break;
64                     }
65                 }
66             }
67         }
68     }
69     cout << max << endl;
70 
71     return 0;
72 }