mirror of
https://github.com/cc65/cc65.git
synced 2024-08-17 03:29:15 +00:00
50 lines
1.1 KiB
C
50 lines
1.1 KiB
C
/*
|
|
!!DESCRIPTION!! solves the "8 queens" chess problem
|
|
!!ORIGIN!! LCC 4.1 Testsuite
|
|
!!LICENCE!! own, freely distributeable for non-profit. read CPYRIGHT.LCC
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
|
|
int up[15], down[15], rows[8], x[8];
|
|
void queens(int c);
|
|
void print(void);
|
|
|
|
int main(void)
|
|
{
|
|
int i;
|
|
for (i = 0; i < 15; i++)
|
|
up[i] = down[i] = 1;
|
|
for (i = 0; i < 8; i++)
|
|
rows[i] = 1;
|
|
queens(0);
|
|
return 0;
|
|
}
|
|
|
|
void queens(int c)
|
|
{
|
|
int r;
|
|
|
|
for (r = 0; r < 8; r++)
|
|
if (rows[r] && up[r-c+7] && down[r+c]) {
|
|
rows[r] = up[r-c+7] = down[r+c] = 0;
|
|
x[c] = r;
|
|
if (c == 7)
|
|
print();
|
|
else
|
|
queens(c + 1);
|
|
rows[r] = up[r-c+7] = down[r+c] = 1;
|
|
}
|
|
}
|
|
|
|
void print(void)
|
|
{
|
|
int k;
|
|
|
|
for (k = 0; k < 8; k++) {
|
|
printf("%c", x[k]+'1');
|
|
if(k<7) printf(" ");
|
|
}
|
|
printf("\n");
|
|
}
|