'commit'

2025-08-30 18:35:01 +08:00
commit 1f397eca87
6258 changed files with 1487241 additions and 0 deletions
--- a/C++专题课程/回溯算法/皇后问题（回溯法）/2N皇后问题解法2.cpp
+++ b/C++专题课程/回溯算法/皇后问题（回溯法）/2N皇后问题解法2.cpp
@@ -0,0 +1,69 @@
+#include<bits/stdc++.h>
+using namespace std;
+//<2F><><EFBFBD>ı<EFBFBD><C4B1><EFBFBD>, ˼·<CBBC><C2B7><EFBFBD>ȷŰ׻ʺ<D7BB>, <20><><EFBFBD>׻ʺ<D7BB><CABA><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD><D6AE>, <20><><EFBFBD><EFBFBD><EFBFBD>Ϸ<EFBFBD><CFB7>úڻʺ<DABB>
+
+#include <bits/stdc++.h>
+using namespace std;
+int n;
+int m[9][9];
+int blackPos[9];
+int whitePos[9];
+int cnt = 0;
+
+// <20>жϵ<D0B6>ǰ<EFBFBD>ܷ<EFBFBD><DCB7><EFBFBD><EFBFBD>ûʺ<C3BB>
+bool isSafe(int pos[], int row) {
+	for(int i = 0; i < row; i++) {
+		if(pos[i] == pos[row] || abs(pos[i] - pos[row]) == abs(i - row)) {
+			return false;
+		}
+	}
+	return true;
+}
+
+// <20>Ժڻʺ<DABB><CABA>ķ<EFBFBD><C4B7>ý<EFBFBD><C3BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
+void blackDfs(int row) {
+	if(row == n) {
+		// <20><><EFBFBD><EFBFBD><EFBFBD>Ѿ<EFBFBD><D1BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>n<EFBFBD><6E><EFBFBD>ڻʺ<DABB>, <20><>ô<EFBFBD>ڷŵķ<C5B5><C4B7><EFBFBD><EFBFBD><EFBFBD>1
+		cnt++;
+		return ;
+	} else {
+		for(blackPos[row] = 0; blackPos[row] < n; blackPos[row]++) {
+			// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰλ<C7B0><CEBB>û<EFBFBD><C3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڻʺ<DABB><CABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͻ, <20><>ǰ<EFBFBD><C7B0><EFBFBD>Է<EFBFBD><D4B7>úڻʺ<DABB><CABA><EFBFBD><EFBFBD>ҵ<EFBFBD>ǰ<EFBFBD><C7B0>λ<EFBFBD><CEBB>û<EFBFBD>з<EFBFBD><D0B7>ð׻ʺ<D7BB>
+			if(isSafe(blackPos, row) && m[row][blackPos[row]] == 1 & blackPos[row] != whitePos[row]) {
+				blackDfs(row+1);
+			}
+		}
+	}
+}
+
+// <20>԰׻ʺ<D7BB><CABA>ķ<EFBFBD><C4B7>ý<EFBFBD><C3BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
+void whiteDfs(int row) {
+	if(row == n) {
+		// <20><><EFBFBD><EFBFBD><EFBFBD>Ѿ<EFBFBD><D1BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>n<EFBFBD><6E><EFBFBD>׻ʺ<D7BB>, <20><><EFBFBD><EFBFBD><EFBFBD>з<EFBFBD><D0B7>úڻʺ<DABB>
+		blackDfs(0);
+		return;
+	} else {
+		for(whitePos[row] = 0; whitePos[row] < n; whitePos[row]++) {
+			// <20><>ǰλ<C7B0><CEBB>û<EFBFBD><C3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>׻ʺ<D7BB><CABA><EFBFBD>ͻ<EFBFBD>ҵ<EFBFBD>ǰλ<C7B0><CEBB><EFBFBD>ܷ<EFBFBD><DCB7><EFBFBD>
+			if(isSafe(whitePos, row) && m[row][whitePos[row]] == 1) {
+				whiteDfs(row+1);
+			}
+		}
+	}
+}
+
+
+int main() {
+	scanf("%d", &n);
+	for(int i = 0; i < n; i++) {
+		for(int j = 0; j < n; j++) {
+			scanf("%d", &m[i][j]);
+		}
+	}
+	whiteDfs(0);
+	printf("%d\n", cnt);
+
+	return 0;
+}
+
+