规范模块目录和第三方依赖结构

third_party/eigen3/doc/examples/TutorialLinAlgExSolveColPivHouseholderQR.cpp

@@ -0,0 +1,17 @@
+#include <iostream>
+#include <Eigen/Dense>
+
+using namespace std;
+using namespace Eigen;
+
+int main()
+{
+   Matrix3f A;
+   Vector3f b;
+   A << 1,2,3,  4,5,6,  7,8,10;
+   b << 3, 3, 4;
+   cout << "Here is the matrix A:\n" << A << endl;
+   cout << "Here is the vector b:\n" << b << endl;
+   Vector3f x = A.colPivHouseholderQr().solve(b);
+   cout << "The solution is:\n" << x << endl;
+}