尝试在C语言sudoku程序中将for循环更改为while循环
尝试在C语言sudoku程序中将for循环更改为while循环
提问于 2018-05-13 04:32:16
我正在尝试解决数独，我已经得到了这个代码，它工作得很好。我想把所有的for循环转换成while循环，我现在已经尝试了几个小时了，但是它不能工作。
以下是原始程序：
#include <stdio.h>
#define SIZE 9
int matrix[9][9] = {
{8,0,0,0,0,0,0,0,0},
{0,0,3,6,0,0,0,0,0},
{0,7,0,0,9,0,2,0,0},
{0,5,0,0,0,7,0,0,0},
{0,0,0,0,4,5,7,0,0},
{0,0,0,1,0,0,0,3,0},
{0,0,1,0,0,0,0,6,8},
{0,0,8,5,0,0,0,1,0},
{0,9,0,0,0,0,4,0,0}
};
void print_sudoku()
{
int i,j;
for(i=0;i<SIZE;i++)
{
for(j=0;j<SIZE;j++)
{
printf("%d\t",matrix[i][j]);
}
printf("\n\n");
}
}
int number_unassigned(int *row, int *col)
{
int num_unassign = 0;
int i,j;
for(i=0;i<SIZE;i++)
{
for(j=0;j<SIZE;j++)
{
if(matrix[i][j] == 0)
{
*row = i;
*col = j;
num_unassign = 1;
return num_unassign;
}
}
}
return num_unassign;
}
int is_safe(int n, int r, int c)
{
int i,j;
for(i=0;i<SIZE;i++)
{
if(matrix[r][i] == n)
return 0;
}
for(i=0;i<SIZE;i++)
{
if(matrix[i][c] == n)
return 0;
}
int row_start = (r/3)*3;
int col_start = (c/3)*3;
for(i=row_start;i<row_start+3;i++)
{
for(j=col_start;j<col_start+3;j++)
{
if(matrix[i][j]==n)
return 0;
}
}
return 1;
}
int solve_sudoku()
{
int row;
int col;
if(number_unassigned(&row, &col) == 0)
return 1;
int n,i;
for(i=1;i<=SIZE;i++)
{
if(is_safe(i, row, col))
{
matrix[row][col] = i;
if(solve_sudoku())
return 1;
matrix[row][col]=0;
}
}
return 0;
}
int main()
{
if (solve_sudoku())
print_sudoku();
else
printf("Error\n");
return 0;
}下面是我尝试过的方法，但不起作用：
#include <stdio.h>
#define SIZE 9
int matrix[9][9] = {
{8,0,0,0,0,0,0,0,0},
{0,0,3,6,0,0,0,0,0},
{0,7,0,0,9,0,2,0,0},
{0,5,0,0,0,7,0,0,0},
{0,0,0,0,4,5,7,0,0},
{0,0,0,1,0,0,0,3,0},
{0,0,1,0,0,0,0,6,8},
{0,0,8,5,0,0,0,1,0},
{0,9,0,0,0,0,4,0,0}
};
void print_sudoku()
{
int i;
int j;
i = 0;
while(i < SIZE)
{
i++;
j = 0;
while(j < SIZE)
{
j++;
printf("%d\t",matrix[i][j]);
}
printf("\n\n");
}
}
int number_unassigned(int *row, int *col)
{
int num_unassign = 0;
int i,j;
for(i=0;i<SIZE;i++)
{
for(j=0;j<SIZE;j++)
{
if(matrix[i][j] == 0)
{
*row = i;
*col = j;
num_unassign = 1;
return num_unassign;
}
}
}
return num_unassign;
}
int is_safe(int n, int r, int c)
{
int i;
int j;
i = 0;
while(i < SIZE)
{
if(matrix[r][i] == n)
i++;
return 0;
}
i = 0;
while(i < SIZE)
{
i++;
if(matrix[i][c] == n)
return 0;
}
int row_start;
i = row_start;
row_start = (r/3)*3;
row_start = (c/3)*3;
/* In particular, this loop in question */
while(i < row_start + 3)
{
i++;
int col_start;
j = col_start;
while(j<col_start + 3)
{
j++;
if(matrix[i][j]==n)
return 0;
}
}
return 1;
}
int solve_sudoku()
{
int row;
int col;
int i;
int n;
i = 1;
if (number_unassigned(&row, &col) == 0)
return 1;
while (i <= SIZE)
{
i++;
if (is_safe(i, row, col))
{
matrix[row][col] = i;
if(solve_sudoku())
return (1);
matrix[row][col] = 0;
}
}
return (0);
}
int main()
{
if (solve_sudoku())
print_sudoku();
else
printf("le sudoku complet et juste\n");
return 0;
}你能帮我一下吗？非常感谢！
回答 2
Stack Overflow用户
发布于 2018-05-13 04:43:10
int i;
for(i = 0;i<n;i++){
//Code inside
}变成了
int i=0;
while(i<n){
//Code inside
i++;
}Stack Overflow用户
发布于 2018-05-13 06:30:42
错误主要发生在从for(i=row_start;i<row_start+3;i++)开始提到的代码段中。您错误地将is_safe()中的这个双循环从：
int row_start = (r/3)*3;
int col_start = (c/3)*3;
for(i=row_start;i<row_start+3;i++)
{
for(j=col_start;j<col_start+3;j++)
{
if(matrix[i][j]==n)
return 0;
}
}添加到此代码。请注意，您混淆了row_start和col_start。
int row_start;
i = row_start;
row_start = (r/3)*3;
row_start = (c/3)*3; // Error occurs here, notice the mis-declaration
while(i < row_start + 3)
{
i++;
int col_start;
j = col_start;
while(j<col_start + 3)
{
j++;
if(matrix[i][j]==n)
return 0;
}
}
return 1;页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/50310446
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