八皇后问题动态演示_Qt5实现

 //核心代码如下
 //Queen--放置皇后

 #include "queue.h"

 queue::queue()
 {
     const int maxn = *;
     this->QN = ;
     this->board = new bool[maxn];
     for (int i = ; i < maxn; i++) {
         this->board[i] = false;
     }
     this->judgeRecursion = true;
     this->count = ;
 }

 queue::queue(int N)
 {
     const int maxn = ;
     if (N >  || N < )
         this->QN = ;    //如果不合法就正规化棋盘
     else
         this->QN = N;
     this->board = new bool[maxn];
     for (int i = ; i < maxn; ++i)  //初始化棋盘，未放置棋子的棋盘设置为false
         this->board[i] = false;
     this->judgeRecursion = true;
     this->count = ;
 }

 bool queue::available (const int Crow, const int Ccol) const  //当前行，当前列
 {
     for (int hor = ; hor < Crow; ++hor) {
         //纵向查找
         if (board[hor * QN + Ccol])     //已经放置皇后的棋盘处为true
             return false;               //则返回false--放置不合法
     }
     int obli = Crow, oblj = Ccol;
     while (obli >  && oblj > ) {
         if (board[(--obli) * QN + (--oblj)])
             return false;              //左斜上查找
     }
     obli = Crow, oblj = Ccol;
     while (obli >  && oblj < QN - ) {
         if (board[(--obli) * QN + (++oblj)])
             return false;              //右斜上查找
     }
     return true;                       //都没有，则该位置可以放置皇后
 }

 //打印棋盘
 void queue::show (bool *Q)
 {
     const int maxn = ;
     for (int i = ; i < maxn; i++)
         Q[i] = this->board[i];
 }

 //重新初始化棋盘
 void queue::reset ()
 {
     const int maxn = ;
     for (int i = ; i < maxn; i++)
         this->board[i] = false;
     this->judgeRecursion = true;
     this->count = ;
 }

 void queue::reset (int N)
 {
     const int maxn = ;
     if (N <  || N > ) this->QN = ;
     else
         this->QN = N;

     for (int i = ; i < maxn; i++)
         this->board[i] = false;
     this->judgeRecursion = true;
     this->count = ;
 }

 queue::~queue ()
 {
     delete []board;
     board = nullptr;
 }

 /**
  * @brief queue::answer --- 放置皇后
  * @param solu --- 求解的方法数
  * @param Crow --- 当前的行数
  * @param Q --- 棋盘,用来打印
  */
 void queue::answer (int solu, int cur, bool *Q)
 {
     if (!judgeRecursion)   //递归结束,中断
         return;
     if (cur == QN) {                  //当前行到最后一行,则一种方案结束
         count++;
         if (count == solu) {          //递归到第solu方案时停止
             this->show (Q);
             judgeRecursion = false;   //停止递归
             return;
         }
         return;
     }
     else
     {
         for (int col = ; col < QN; col++)
         {
             if (available (cur, col))         //检查当前行,列
             {
                 board[cur * QN + col] = true; //合法则放置皇后
                 answer (solu, cur + , Q);    //递归下一行
                 //如果回溯法中使用了辅助的全局变量,则一定要及时把它们恢复原状.
                 //特别的,若函数有多个出口,则需在每个出口处恢复被修改的值
                 board[cur * QN + col] = false;
             }
         }
     }
 }

源代码下载地址:链接：https://pan.baidu.com/s/12BTDR8pRMvxpKYNFb988EQ 密码：yk0o