八皇后问题 

  1 #include <stdio.h>
  2 #include <stdlib.h>
  3 #include "../Stack/stack.h"
  4 
  5 typedef struct
  6 {
  7     int row;
  8     int col;
  9 } POSITION;
 10 
 11 int getSize(void);
 12 
 13 void fillBoard(STACK* stack, int boardSize);
 14 void printBoard(STACK* stack, int boardSize);
 15 
 16 bool guarded(int board[][9], int row, int col, int boardSize);
 17 
 18 int main(void)
 19 {
 20     int boardSize;
 21 
 22     STACK* stack;
 23     boardSize = getSize();
 24     stack = createStack();
 25 
 26     fillBoard(stack, boardSize);
 27     printBoard(stack, boardSize);
 28     destroyStack(stack);
 29 
 30     printf("\nWe hope you enjoyed Eight Queens.\n");
 31     return 0;
 32 }
 33 
 34 int getSize(void)
 35 {
 36     int boardSize;
 37 
 38     printf("Welcome to EightQueens. You may select\n"
 39            "a board sizei from 4 x 4 to 8 x 8. I will \n"
 40            "then position a queen in ezch row of the\n"
 41            "board so no queen may capture another\n"
 42            "queen. Note: There are no solutions for boards \n"
 43            "less than 4 x 4.\n");
 44     printf("\nPlease enter the board size: ");
 45     scanf("%d", &boardSize);
 46     while(boardSize < 4 || boardSize > 8){
 47         printf("Board size must be greater than 3 and less than 9.\n"
 48                "You entered %d. Please re-enter.\n"
 49                "Thankyou.\a\a\n\n"
 50                "Your board size: ", boardSize);
 51         scanf("%d", &boardSize);
 52     }
 53     return boardSize;
 54 }
 55 
 56 void fillBoard(STACK* stack, int boardSize)
 57 {
 58     int row;
 59     int col;
 60     int board[9][9] = {0};
 61     POSITION* pPos;
 62 
 63     row = 1;
 64     col = 0;
 65 
 66     while(row <= boardSize){
 67         while(col <= boardSize && row <= boardSize){
 68             col++;
 69             if(!guarded(board, row, col, boardSize)){
 70                 board[row][col] = 1;
 71 
 72                 pPos = (POSITION*)malloc(sizeof(POSITION));
 73                 pPos->row = row;
 74                 pPos->col = col;
 75 
 76                 pushStack(stack, pPos);
 77 
 78                 row++;
 79                 col = 0;
 80             }
 81             while(col >= boardSize){
 82                 pPos = popStack(stack);
 83                 row = pPos->row;
 84                 col = pPos->col;
 85                 board[row][col] = 0;
 86                 free(pPos);
 87             }
 88         }
 89     }
 90     return;
 91 }
 92 
 93 bool guarded(int board[][9], int chkRow, int chkCol, int boardSize)
 94 {
 95     int row;
 96     int col;
 97 
 98     // Check current col for a queen
 99     col = chkCol;
100     for(row = 1; row <= chkRow; row++)
101         if(board[row][col] == 1)
102             return true;
103 
104     // Check diagonal right-up
105     for(row = chkRow - 1, col = chkCol + 1;
106         row > 0 && col <= boardSize;
107         row--, col++)
108         if(board[row][col] == 1)
109             return true;
110 
111     // Check diagonal left-up
112     for(row = chkRow - 1, col = chkCol - 1;
113         row > 0 && col > 0;
114         row--, col--)
115         if(board[row][col] == 1)
116             return true;
117 
118     return false;
119 }
120 
121 void printBoard(STACK* stack, int boardSize)
122 {
123     int col;
124 
125     POSITION* pPos;
126     STACK* pOutStack;
127 
128     if(emptyStack(stack)){
129         printf("There are no positions on this board\n");
130         return;
131     }
132 
133     printf("\nPlace queens in following positions:\n");
134 
135     pOutStack = createStack();
136     while(!emptyStack(stack)){
137         pPos = popStack(stack);
138         pushStack(pOutStack, pPos);
139     }
140 
141     while(!emptyStack(pOutStack)){
142         pPos = popStack(pOutStack);
143         printf("Row %d-Col %d: \t|", pPos->row, pPos->col);
144         for(col = 1; col <= boardSize; col++){
145             if(pPos->col == col)
146                 printf("Q |");
147             else
148                 printf("  |");
149         }
150         printf("\n");
151     }
152     destroyStack(pOutStack);
153     return;
154 }

 

posted @ 2020-02-28 14:51  张乐珊  阅读(138)  评论(0)    收藏  举报