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@@ -0,0 +1,54 @@
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+/*
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+ * @Description:
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+ * @Version: 1.0
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+ * @Autor: zhuyijun
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+ * @Date: 2021-11-11 22:23:35
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+ * @LastEditTime: 2021-11-11 23:02:49
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+ */
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+#include <bits/stdc++.h>
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+using namespace std;
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+vector<vector<string>> res;
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+bool isVaild(vector<string> &board, int row, int col) {
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+ int n = board.size();
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+ // 检查列
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+ for (int i = 0; i < row; i++) { // 这是一个剪枝
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+ if (board[i][col] == 'Q') {
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+ return false;
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+ }
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+ }
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+ // 检查 45度角是否有皇后
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+ for (int i = row - 1, j = col - 1; i >= 0 && j >= 0; i--, j--) {
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+ if (board[i][j] == 'Q') {
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+ return false;
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+ }
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+ }
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+ // 检查 135度角是否有皇后
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+ for (int i = row - 1, j = col + 1; i >= 0 && j < n; i--, j++) {
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+ if (board[i][j] == 'Q') {
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+ return false;
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+ }
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+ }
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+ return true;
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+}
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+
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+void backtrack(vector<string> &board, int row) {
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+ if (row == board.size()) {
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+ res.push_back(board);
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+ return;
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+ }
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+ auto result = board[row];
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+ for (int col = 0; col < result.size(); col++) {
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+ if (!isVaild(board, row, col)) {
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+ continue;
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+ }
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+ board[row][col] = 'Q';
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+ backtrack(board, row + 1);
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+ board[row][col] = '.';
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+ }
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+}
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+vector<vector<string>> solveNQueens(int n) {
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+ vector<string> board(n, string(n, '.'));
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+ backtrack(board, 0);
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+ return res;
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+}
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+int main() { return 0; }
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