void queens(int (*queen)[size],int row){
if(row == size){
count ++;
printf("==========count = %d=======\n",count);
for(int i = 0 ; i < size; i++){
for(int j = 0 ;j<size;j++){
if(queen[i][j] == 1){
printf("%3d",1);
}else{
printf("%3d",0);
}
}
printf("\n");
}
printf("===========================\n\n");
}
/* printf("#1.running\n"); */
for(int i = 0 ; i < size ;i++){
int flag = 1;
for(int j = 0 ; j<row;j++){
if(i == c[j] || c[j] - j == i - row || j+c[j] == i+row ){
flag = 0;
break;
}
}
if(flag){
c[row] = i;
queen[row][i] = 1;
queens(queen,row+1);
queen[row][i] = 0;
}
}
/* printf("running\n"); */
}
int main()
{
struct timespec ts_start;
struct timespec ts_end;
FILE *fp = fopen("queens_c.dat", "w");
if (!fp) {
fprintf(stderr, "Cannot open data file\n");
exit(1);
}
for (int i = 1; i <= max; i++){
clock_gettime(CLOCK_MONOTONIC, &ts_start);
int solution = queens(i);
clock_gettime(CLOCK_MONOTONIC, &ts_end);
struct timespec time = diff(ts_start, ts_end);
double t = (double) time.tv_sec * 1000.0 + (double)time.tv_nsec / 1000000.0;
printf("%d queens: %lf ms.\n", i, t);
fprintf(fp, "%d\t%lf\n", i, t);
if (solutions[i-1] != solution){
printf("Invalid result!\n");
exit(1);
}
}
return 0;
}
int totalNQueens(int n) {
vector<int> columns;
if(n == 0){
return 0;
}
return queens(columns, n);
}
void queens(int i)
{
char resp;
for(t[i]=1;t[i]<=8;t[i]++)
{
if(empty(i))
{
if(i==8)
{
print_solution();
/* If this exit is commented, it will show ALL possible combinations */
printf ("\nType any letter to get another solution (Q for Quit): \n");
scanf (" %c",&resp);
if (resp== 'Q') exit(0);
//getch();
//exit(0);
//getch();
}
else
{
// Recurse!
queens(i+1);
}
}// if
}// for
}
int main()
{
clrscr();
queens(1);
print_solution();
getch();
return(0);
}
vector<vector<string> > solveNQueens(int n) {
vector<int> columns;
vector<vector<string> > ret;
if(n == 0){
return ret;
}
queens(columns, n, ret);
return ret;
}
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;
}
int main(int argc, char const *argv[]) {
system("clear");
int i;
int n = 0;
scanf("%d", &n);
printf("board size,calls,time\n");
for (i = 0; i <= n; i++) {
queens(i);
}
return 0;
}
main()
{
long i;
printf("generates 92 solutions. \n15863724 is first\n\n");
for (i = 0; i < 15; i++)
up[i] = down[i] = 1;
for (i = 0; i < 8; i++)
rows[i] = 1;
queens(0);
printf("...and...\n84136275 is last\nTook about 58 sec on 1.6mhz elf with St Judy's compiler\n");
return 0;
}
int main(){
int n;
// solution is n-queens. allow user to select dimensions via
printf("Enter board size. ie NxN\n");
scanf("%d", &n);
queens(1,n);
print_solutions(n);
return 0;
}
void queens(int i) {
for(t[i] = 1; t[i]<=8; t[i]++) {
if(empty(i)) {
if(i==8) {
printSolution();
exit(0);
//return;
}
else {
queens(i+1);
}
}
}
}
int queens(vector<int> columns, int n){
int row, col, ret(0);
row = columns.size();
if(row == n){
return 1;
}
for(col = 0; col < n; col++){
if(check(columns, row, col)){
columns.push_back(col);
ret += queens(columns, n);
columns.pop_back();
}
}
return ret;
}
void queens(int i) {
int j;
for(t[i]=0; t[i]<8; t[i]++) {
for(j=0; t[i]!=t[j] && abs(t[i]-t[j])!=abs(i-j) && j<8; j++);
if(i==j) {
if(i==7) {
print();
}
else
queens(i+1);
}
}
}
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 queens(int i)
{
for(t[i]=1;t[i]<=N;t[i]++)
{
if(empty(i))
{
if(i==N)
{
print_solution();
//exit(0);
}
else
queens(i+1);
}
}
}
int queens(c)
{
long r;
//printf("queens(%d)\n",c);
for (r = 0; r < 8; r++){
//printf("\trows[%d]=%d\n",r,rows[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 queens(int r,int n){
// recursive backtracking function
// r = row, n = board dimension
int c ; // column
for (c = 1; c <= n ; c++){
if(setQ(r,c)){ // if we are allowed to set the queen
x[r-1] = c;
if (r == n){ // no more columns to attempt to set
save(n);
} else{
queens(r+1,n);
x[r-1] = 0; // backtrack!
}
}
}
iterations++;
}
void queens(vector<int> columns, int n, vector<vector<string> >& ret){
int row, col;
row = columns.size();
if(row == n){
string s(n, '.');
vector<string> temp(n, s);
for(int i = 0; i < n; i++){
temp[i][columns[i]] = 'Q';
}
ret.push_back(temp);
return;
}
for(col = 0; col < n; col++){
if(check(columns, row, col)){
columns.push_back(col);
queens(columns, n, ret);
columns.pop_back();
}
}
return;
}
int main(int argc, char* argv[]){
queens(1);
printSolution();
return 0;
}
int main() {
queens(0);
return 0;
}
void main()
{
queens(1);
printf("\n..%d solutionas..",cnt);
}
