C++_学习笔记_地图填色问题

 

 回溯  /  递归

首先判断传入的颜色是否为最后的颜色’d’，如果是说明至少还得向上回溯一次。

如果一切正常不是’d’的话，那就开始填色。

遍历与之相邻的是否重色，如果重色 则本区域取下一色，直到递归传入’d’为之

如果不重色就从第一个颜色开始试探下一区域。

 

  1 #include<iostream>
  2 #include<vector>
  3 using namespace std;
  4 
  5 struct region {
  6     int id;
  7     region* next;
  8     region* last;
  9 }r1,r2,r3,r4,r5,r6,r7;
 10 
 11 int a[7][7] = { {0,1,1,1,1,1,0},{1,0,0,0,0,1,0},{1,0,0,1,1,0,0},{1,0,1,0,1,1,0},{1,0,1,1,0,1,0},{1,1,0,1,1,0,0},{0,0,0,0,0,0,0} };
 12 
 13 int fill(region currentRegion,int currentColor,int a[7][7],int* result ) {
 14     //先判断传入颜色是否是d，如果是的话说明还要向上回溯
 15     if (currentColor <'d')
 16     {
 17         result[currentRegion.id - 1] = ++currentColor;
 18         //判断是否重色
 19         bool isrepeat = false;
 20         int temp;
 21         for (int i = 0; i < 7; i++) {
 22             if (a[currentRegion.id - 1][i] == 1) {
 23                 if (currentColor == result[i]) {
 24                     temp = i;
 25                     isrepeat = true;
 26                     break;
 27                 }
 28             }
 29 
 30         }
 31         if (isrepeat) {
 32             //先判断是否需要回溯
 33             cout << currentRegion.id << "is repeat with" << temp + 1 << "," << currentColor << endl;
 34             if (currentColor == 'd') {
 35                 int rullbackNumber = result[currentRegion.id - 2] + 1;
 36                 result[currentRegion.id - 1] = 0;
 37                 currentRegion = *currentRegion.last;
 38                 fill(currentRegion, rullbackNumber, a, result);
 39             }
 40             else {
 41                 //如果重复，填下一个颜色
 42 
 43                 fill(currentRegion, currentColor, a, result);
 44             }
 45 
 46         }
 47         else {
 48             if (currentRegion.next)
 49                 fill(*currentRegion.next, 96, a, result);
 50             else
 51                 return 0;
 52         }
 53     }
 54     else {
 55         int rullbackNumber = result[currentRegion.id - 2] + 1;
 56         result[currentRegion.id - 1] = 0;
 57         currentRegion = *currentRegion.last;
 58         fill(currentRegion, rullbackNumber, a, result);
 59     }
 60      
 61 }
 62 
 63 void dispArr(int* arr, int n)
 64 {
 65     for (int i = 0; i < n; i++)
 66     {
 67         char temp = arr[i];
 68         cout << "arr" << "[" << i +1<< "]" << " is:" << temp << endl;
 69     }
 70 }
 71 
 72 
 73 
 74 int main() {
 75     r1.id = 1;
 76     r2.id = 2;
 77     r3.id = 3;
 78     r4.id = 4;
 79     r5.id = 5;
 80     r6.id = 6;
 81     r7.id = 7;
 82     r1.last = nullptr;
 83     r1.next = &r2;
 84     r2.last = &r1;
 85     r2.next = &r3;
 86     r3.last = &r2;
 87     r3.next = &r4;
 88     r4.last = &r3;
 89     r4.next = &r5;
 90     r5.last = &r4;
 91     r5.next = &r6;
 92     r6.last = &r5;
 93     r6.next = &r7;
 94     r7.last = &r6;
 95     r7.next = nullptr;
 96 
 97     int* result = new int[7]{0,0,0,0,0,0,0};
 98 
 99     int x=fill(r1,96,a,result);
100     dispArr(result, 7);
101 
102     delete result;
103 }

 

 

 

 

 

感谢，https://www.cnblogs.com/walter-xh/p/6192800.html

 

posted @ 2020-05-01 01:55  vantablack  阅读(857)  评论(0)  编辑  收藏  举报