本文主要是介绍1128. N Queens Puzzle (20),希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
1128. N Queens Puzzle (20)
时间限制 300 ms 内存限制 65536 kB 代码长度限制 16000 B
判题程序 Standard 作者 CHEN, Yue
The “eight queens puzzle” is the problem of placing eight chess queens on an 8×8 chessboard so that no two queens threaten each other. Thus, a solution requires that no two queens share the same row, column, or diagonal. The eight queens puzzle is an example of the more general N queens problem of placing N non-attacking queens on an N×N chessboard. (From Wikipedia - “Eight queens puzzle”.)
Here you are NOT asked to solve the puzzles. Instead, you are supposed to judge whether or not a given configuration of the chessboard is a solution. To simplify the representation of a chessboard, let us assume that no two queens will be placed in the same column. Then a configuration can be represented by a simple integer sequence (Q1, Q2, …, QN), where Qi is the row number of the queen in the i-th column. For example, Figure 1 can be represented by (4, 6, 8, 2, 7, 1, 3, 5) and it is indeed a solution to the 8 queens puzzle; while Figure 2 can be represented by (4, 6, 7, 2, 8, 1, 9, 5, 3) and is NOT a 9 queens’ solution.
Figure 1
Figure 2
Input Specification:
Each input file contains several test cases. The first line gives an integer K (1 < K <= 200). Then K lines follow, each gives a configuration in the format “N Q1 Q2 … QN”, where 4 <= N <= 1000 and it is guaranteed that 1 <= Qi <= N for all i=1, …, N. The numbers are separated by spaces.
Output Specification:
For each configuration, if it is a solution to the N queens problem, print “YES” in a line; or “NO” if not.
Sample Input:
4
8 4 6 8 2 7 1 3 5
9 4 6 7 2 8 1 9 5 3
6 1 5 2 6 4 3
5 1 3 5 2 4
Sample Output:
YES
NO
NO
YES
坑点:题目保证了不在同一列,但是没有保证不在同一行, 所以要加特殊判断是否位于同一行
#define _CRT_SECURE_NO_WARNINGS
#include <algorithm>
#include <iostream>
#include <cmath>using namespace std;
const int MaxN = 1010;
int row[MaxN], N;bool Judge() {for (int i = 1; i < N; ++i) {for (int k = i + 1; k <= N; ++k) {if ((row[i] == row[k]) || k - i == abs(row[i] - row[k])) return false;}}return true;
}int main() {
#ifdef _DEBUGfreopen("data.txt", "r+", stdin);
#endif // _DEBUGstd::ios::sync_with_stdio(false);int n; cin >> n;while (n--) {cin >> N;for (int i = 1; i <= N; ++i) cin >> row[i];bool valid = Judge();valid ? (cout << "YES\n") : (cout << "NO\n");}return 0;
}
这篇关于1128. N Queens Puzzle (20)的文章就介绍到这儿,希望我们推荐的文章对编程师们有所帮助!