c++容器问题

[sinat_33495068]

void divide(double A[3], double B[3], double C[3], vector<double *> &vec)
{
	double ab[3], ac[3], bc[3];
	//线段ab的中点ab
	ab[0] = (A[0] + B[0]) / 2;
	ab[1] = (A[1] + B[1]) / 2;
	ab[2] = (A[2] + B[2]) / 2;
	//线段ac的中点ac
	ac[0] = (A[0] + C[0]) / 2;
	ac[1] = (A[1] + C[1]) / 2;
	ac[2] = (A[2] + C[2]) / 2;
	//线段bc的中点bc
	bc[0] = (B[0] + C[0]) / 2;
	bc[1] = (B[1] + C[1]) / 2;
	bc[2] = (B[2] + C[2]) / 2;
	//将四个面的坐标存入容器vec
	vec.push_back(A);
	vec.push_back(ab);
	vec.push_back(ac);

	vec.push_back(ab);
	vec.push_back(B);
	vec.push_back(bc);

	vec.push_back(ab);
	vec.push_back(ac);
	vec.push_back(bc);

	vec.push_back(ac);
	vec.push_back(bc);
	vec.push_back(C);
}
int main()
{
	vector<double *> vec;
	double dian1[3] = { 0, 0, 0 }, dian2[3] = { 0, 1, 0 }, dian3[3] = { 1, 0, 0 };
	divide(dian1, dian2, dian3, vec);
	cout << endl;
	for (int i = 0; i != 12; i++)
		for (int j = 0; j != 3; ++j)
			cout << vec[i][j] << " ";
}

不知道程序哪里出问题了，为什么输出的事错误的。

[幻夢之葉]

返回了局部变量的指针，局部变量在函数退出之后就被销毁了 struct Point { double x; double y; double z; } void divide(Point A, Point B, Point C, vector<Point> &vec) { Point AB, BC, AC; AB.x = (A.x + B.x) / 2; AB.y = (A.y + B.y) / 2; AB.z = (A.z + B.z) / 2; ... ... ... vec.push(A); vec.push(AB); }

[真相重于对错]

因为你vector<double*>是把局部变量的地址存入了vector，离开函数后，那个地址就失效了 ab ac bc 不能用数组，而是建立在堆上指针 double* ab, *ac,*bc; ab = new double[3]; ac = new double[3]; bc =new double[3]; 程序结束后记住 要 delete []ab; .....

[sinat_33495068]

引用 1 楼 jianwen0529 的回复:

返回了局部变量的指针，局部变量在函数退出之后就被销毁了 struct Point { double x; double y; double z; } void divide(Point A, Point B, Point C, vector<Point> &vec) { Point AB, BC, AC; AB.x = (A.x + B.x) / 2; AB.y = (A.y + B.y) / 2; AB.z = (A.z + B.z) / 2; ... ... ... vec.push(A); vec.push(AB); }

多谢啊，受教了。

[sinat_33495068]

引用 2 楼 hdt 的回复:

因为你vector<double*>是把局部变量的地址存入了vector，离开函数后，那个地址就失效了 ab ac bc 不能用数组，而是建立在堆上指针 double* ab, *ac,*bc; ab = new double[3]; ac = new double[3]; bc =new double[3]; 程序结束后记住 要 delete []ab; .....

多谢，受教了。