HDU 2553 N Queen problem Classic search, DFS solution

N Queen's questionTime limit:2000/1000 MS (java/others) Memory limit:32768/32768 K (java/others)
Total submission (s): 10239 Accepted Submission (s): 4609


Problem description placed n Queens on the N*n's checkered chessboard, making them not attack each other (that is, any 2 queens are not allowed to be in the same row, in the same column, or in a diagonal line with a 45-angle checkerboard border.)
Your task is to find out how many legal placement methods are available for a given n.


Input has several lines, one positive integer n≤10 per line, indicating the number of boards and queens, or, if n=0, the end.
Output has several rows, one positive integer per line, representing the number of different placements of the queen corresponding to the input row.
Sample Input

1850

Sample Output

19210

Authorcgf
The code explains everything code:

#include <stdio.h> #define MAX 15int n, ans = 0, res[max],map[max];void DFS (int row) {if (row = n) {ans++; return;} for (int i = 0; i < n; ++i) {bool flag = false; Map[row] = i, for (int j = 0; j < row; ++j) {if (map[row]==map[j]| | map[row]-row==map[j]-j| | MAP[ROW]+ROW==MAP[J]+J) {flag = true; break;}} if (!flag) {DFS (row+1);}}} int main () {for (int i = 1; i <=; ++i) {n = i; ans = 0;D fs (0); Res[i] = ans;} while (~SCANF ("%d", &n) && N) {printf ("%d\n", Res[n]);} return 0;}

with June

HDU 2553 N Queen problem Classic search, DFS solution