Merge pull request #4 from Rajeshjha586/master

N_Queen.cpp

Backtracking/N_Queen.cpp

@@ -0,0 +1,61 @@
+#include<iostream>
+#include<vector>
+
+using namespace std;
+
+vector<bool> ROWS;
+vector<bool> COLS;
+vector<bool> DIAG;
+vector<bool> ADIAG;
+int N_Queen_Problem_Combination_06(int n, int m, int idx, int tnq, string ans)
+{
+    if(tnq==0)
+    {
+        cout << ans << endl;
+        return 1;
+    }
+
+    int count=0;
+    for(int r=idx; r<n*m; r++)
+    {
+        int x = r / m;
+        int y = r % m;
+
+        if(!ROWS[x] && !COLS[y] && !DIAG[x+y] && !ADIAG[x-y+(m-1)])
+        {
+            ROWS[x]=true; COLS[y]=true; DIAG[x+y]=true; ADIAG[x-y+(m-1)]=true;
+
+            count += N_Queen_Problem_Combination_06(n, m, r+1, tnq-1, ans+"("+to_string(x)+","+to_string(y)+") ");
+
+            ROWS[x]=false; COLS[y]=false; DIAG[x+y]=false; ADIAG[x-y+(m-1)]=false;
+
+        }
+    }
+
+    return count;
+}
+
+void Questions_Set_01()
+{
+    int n=10;
+    int m=10;
+    int tnq=10;
+
+    ROWS.resize(n, false);
+    COLS.resize(m, false);
+    DIAG.resize(n+m-1, false);
+    ADIAG.resize(n+m-1, false);
+
+    cout << N_Queen_Problem_Combination_06(n, m, 0, tnq, "") << endl;
+}
+
+void solve()
+{
+    Questions_Set_01();
+}
+
+int main()
+{
+    solve();
+    return 0;
+}