'commit'

C++专题课程/基础知识/2N皇后问题.cpp

@@ -0,0 +1,47 @@
+#include<bits/stdc++.h>
+// https://blog.csdn.net/qq_41923622/article/details/79756107
+using namespace std;
+int  a[10][10];
+int bj[3][20]= {0};
+int bj1[3][20]= {0};
+int n;
+int sum=0;
+void f2(int x ) {
+	int y;
+	if(x==n)sum++;
+	else {
+		for(y=0; y<n; y++)
+			if(a[x][y]==1&&bj1[0][y]==0&&bj1[1][x+y]==0&&bj1[2][x-y+n]==0) {
+				a[x][y]=3;
+				bj1[0][y]=bj1[1][x+y]=bj1[2][x-y+n]=1;
+				f2(x+1);
+				bj1[0][y]=bj1[1][x+y]=bj1[2][x-y+n]=0;
+				a[x][y]=1;
+			}
+	}
+}
+void f(int x ) { //<2F><><EFBFBD>ð׺<C3B0>
+	int y;
+	if(x==n)f2(0);//<2F><><EFBFBD><EFBFBD> <20>ں<EFBFBD>
+	else {
+		for(y=0; y<n; y++)
+			if(a[x][y]==1&&bj[0][y]==0&&bj[1][x+y]==0&&bj[2][x-y+n]==0) { //<2F><><EFBFBD>ҶԽ<D2B6> <20><> <20>͵<EFBFBD>ǰ<EFBFBD><C7B0><EFBFBD>궼δ<EAB6BC><CEB4><EFBFBD><EFBFBD><EFBFBD>ǿɷ<C7BF>
+				a[x][y]=2;//<2F><><EFBFBD>ǰ׺<C7B0> <20><><EFBFBD><EFBFBD>λ<EFBFBD><CEBB> Ϊ<><CEAA><EFBFBD><EFBFBD><EFBFBD>úں<C3BA> <20><><EFBFBD><EFBFBD>
+				bj[0][y]=bj[1][x+y]=bj[2][x-y+n]=1;//<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҶԽ<D2B6> <20><>
+				f(x+1);
+				bj[0][y]=bj[1][x+y]=bj[2][x-y+n]=0;//<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
+				a[x][y]=1;
+			}
+	}
+}
+int main() {
+	int i,j;
+	scanf("%d",&n);
+	for(i=0; i<n; i++)
+		for(j=0; j<n; j++)
+			scanf("%d",&a[i][j]);
+	f(0);
+	printf("%ld\n",sum);
+	return 0;
+}
+