深度优先搜索 之 CODE[VS] 1116 四色问题

/*
dfs，需要注意输入的测试数据的格式。
*/

 1 #include <iostream>
 2 #include <cstdlib>
 3 #include <cstdio>
 4 #include <cstddef>
 5 #include <iterator>
 6 #include <algorithm>
 7 #include <string>
 8 #include <locale>
 9 #include <cmath>
10 #include <vector>
11 #include <cstring>
12 #include <map>
13 #include <utility>
14 #include <queue>
15 #include <stack>
16 #include <set>
17 using namespace std;
18 const int INF = -0x3f3f3f3f;
19 const int MaxN = 55;
20 const int modPrime = 3046721;
21
22 int n;
23 int colorArr[10];
24 char imap[10][10];
25 int answer = 0;
26
27 bool isAdjoinColor(int node, int color)
28 {
29     for (int i = 0; i < n; ++i)
30     {
31         if ((imap[node][i] == ‘1‘) && (color == colorArr[i]))
32         {
33             return true;
34         }
35     }
36     return false;
37 }
38
39 void Solve(int nodeNum)
40 {
41     if (nodeNum == n)
42     {
43         ++answer;
44         return;
45     }
46     for (int color = 1; color <= 4; ++color)
47     {
48         if (!isAdjoinColor(nodeNum, color))
49         {
50             colorArr[nodeNum] = color;
51             Solve(nodeNum + 1);
52             colorArr[nodeNum] = -1;
53         }
54     }
55 }
56
57
58 int main()
59 {
60 #ifdef HOME
61     freopen("in", "r", stdin);
62     //freopen("out", "w", stdout);
63 #endif
64
65     fill(colorArr, colorArr + 10, -1);
66     cin >> n;
67     for (int i = 0; i < n; ++i)
68     {
69         for (int j = 0; j < n; ++j)
70         {
71             cin >> imap[i][j];
72         }
73     }
74     Solve(0);
75     cout << answer << endl;
76
77
78 #ifdef HOME
79     cerr << "Time elapsed: " << clock() / CLOCKS_PER_SEC << " ms" << endl;
80     _CrtDumpMemoryLeaks();
81 #endif
82     return 0;
83 }