int totalNQueens(int n) {
// IMPORTANT: Please reset any member data you declared, as
// the same Solution instance will be reused for each test case.
vector<int> row(n + 1);
int sum = 0;
putQueen(row, 1, n, sum);
return sum;
}
int totalNQueens(int n) {
result = 0;
int *pos = new int[n];
putQueen(pos, 0, n);
delete []pos;
return result;
}
int main(){
struct queen q;
int n;
printf("請輸入皇后數：");
scanf("%d", &n);
initQueen(&q, n);
putQueen(&q, 1);
printf("八皇后問題共有%d組解\n", q.solutions);
return 0;
}
void putQueen(int* pos, int line, int N){
if(line >= N){
takeRecord(pos, N);
return;
}
for(int i=0; i<N; i++){
pos[line] = i;
if(valid(pos, line, N))
putQueen(pos, line+1, N);
}
}
void putQueen(vector<int> &queenPos, int row, int n, int &result) {
if (row == n) {
result++;
return;
}
for (int col = 0; col < n; col++) {
if (check(queenPos, row, col, n)) {
queenPos[row] = col;
putQueen(queenPos, row+1, n, result);
queenPos[row] = -1;
}
}
}
void putQueen(vector<int> &row, int n, int total, int &sum) {
int i, j;
for (i = 1;i <= total;i++) {
for (j = 1;j < n;j++)
if (i == row[j] || n - j == abs(i - row[j]))
break;
if (j == n) {
if (n == total) {
sum++;
return;
}
row[n] = i;
putQueen(row, n + 1, total, sum);
row[n] = 0;
}
}
}
void putQueen(struct queen *q, int row) {
int i, j, pos;
if (row > q->n) { //已經放n上皇后了
q->solutions++;
for (i = 1; i <= q->n; i++) {
for (j = 1; j <= q->n; j++) {
if (q->board[i*(q->n+2)+j] == 'Q')
printf("后");
else
printf("口");
}
printf("\n");
}
printf("\n");
return;
}
//開始畫減, 再row列放上皇后
for (i = 1; i <= q->n; i++) {
//若此位置沒有其他皇后吃得到
if(q->board[row*(q->n+2)+i] == 0) {
//放上皇后
q->board[row*(q->n+2)+i] = 'Q';
//設定下方勢力範圍, 共有3個方向要設定
for (j = 0; j < 3; j++) {
for (pos = row*(q->n+2)+i+q->dir[j]; q->board[pos] >= 0; pos += q->dir[j]) {
q->board[pos]++;
}
}
//開始recusion放下一個皇后
putQueen(q, row+1);
//回復原來的狀態
//移除皇后
q->board[row*(q->n+2)+i] = 0;
//反射訂下方式一範圍共有三個方向要設定
for (j = 0; j < 3; j++) {
for (pos = row*(q->n+2)+i+q->dir[j]; q->board[pos] >= 0; pos += q->dir[j]) {
q->board[pos]--;
}
}
}
}
}
int totalNQueens(int n) {
int result = 0;
vector<int> queenPos(n, -1);
putQueen(queenPos, 0, n, result);
return result;
}
