N皇后(有误)

//A1.java

public class A1 {

	private final static int N = 5;

	public static void main(String[] args) {
		exec();
	}

	// 执行
	public static void exec() {
		int a[][] = new int[N][N];

		for (int i = 0; i < N; i++) {
			reset(a);
			a[0][i] = 1;
			int b = 1;
			for (int j = 1; j < N; j++) {
				int c = 0;
				for (int k = 0; k < N; k++) {
					if (check(a, j, k)) {
						a[j][k] = 1;
						c = 1;
						break;
					}
				}
				if (c == 0) {
					b = 0;
					break;
				}

			}
			if (b == 1) {
				printResult(a);
			}
		}
	}

	// 检查
	public static boolean check(int a[][], int j, int k) {
		// 左上
		for (int i = 1; j - i >= 0 && k - i >= 0; i++) {
			if (a[j - i][k - i] == 1) {
				return false;
			}
		}
		// 正上
		for (int i = 1; j - i >= 0; i++) {
			if (a[j - i][k] == 1) {
				return false;
			}
		}
		// 右上
		for (int i = 1; j - i >= 0 && k + i < N; i++) {
			if (a[j - i][k + i] == 1) {
				return false;
			}
		}
		return true;
	}

	// 显示结果
	public static void printResult(int a[][]) {
		for (int i = 0; i < N; i++) {
			for (int j = 0; j < N; j++) {
				if (a[i][j] == 1) {
					System.out.print("(" + i + "," + j + ") ");
				}
			}
		}
		System.out.println();
	}

	// 数组全部置0
	public static void reset(int a[][]) {
		for (int i = 0; i < N; i++) {
			for (int j = 0; j < N; j++) {
				a[i][j] = 0;
			}
		}
	}
}

 

运行结果：

 

(0,0) (1,2) (2,4) (3,1) (4,3)
(0,1) (1,3) (2,0) (3,2) (4,4)
(0,2) (1,0) (2,3) (3,1) (4,4)
(0,3) (1,0) (2,2) (3,4) (4,1)