C++按升序对指针数组进行排序

Question

我有这个函数，其中 2 个 vector 相互比较，程序找到 vector 的平方差之和。

    double Search::NNS(vector<vector<double>> bb, vector<vector<double>> aa)
    {
        int M = 768; int N = 1024;
        int R = 49; int C = 36;
        //double SSD[] = MainVectorBlock[] - WallyVector[];
        //double SSD[] = SSD[] * SSD[];
        //sum = sum + SSD[];

    vector<vector<double>> &MainIMG = bb;
    vector<vector<double>> &WallyIMG = aa;
    double *SSD = new double[R*C];
    double sum = 0;


    for (int bx = 0; bx < M; bx += R)
        for (int by = 0; by < N; by += C)
        {
            Compare = new double*[R];
            for (int x = 0; ((x < R) && ((bx + x) < M)); ++x)
            {
                Compare[x] = new double[R];
                for (int y = 0; ((y < C) && ((by + y) < N)); ++y)
                {
                    if ((bx + x) >= M)
                    {
                        cout << Compare[bx + x] << Compare[by + y] << " ";

                    }

                    //cout << MainIMG[bx + x][by + y] << " ";
                    Compare[x][y] = MainIMG[bx + x][by + y] - WallyIMG[x][y];
                    Compare[x][y] = Compare[x][y] * Compare[x][y];
                    //sum += Compare[x][y];
                    SSD[R*C] += Compare[x][y];
                    //SSD[R*C] = sum;
                    //cout << Compare[x][y] << " ";
                }

            }
            //cout << "\n\n\n" << endl;
            //cout << sum << endl;
            //cout << SSD[R*C] << "\t" << sum << endl;

            for (int i = 0; i < R*C; i++)
            {
                for (int j = 0; j < R*C; j++)
                {
                    if (SSD[i] > SSD[j])
                    {
                        int temp = SSD[i];
                        SSD[i] = SSD[j];
                        SSD[j] = temp;
                    }
                }
            }

        }
    for (int a = 0; a < R*C; a++)
    {
        cout << SSD[a] << endl;
    }

    return 0;
}

我可以显示所有差值平方和，但是当我尝试按升序对这些值进行排序时，我一直得到这个值 -6.27744e+66。 我尝试更改循环并将其放置在整个主 for 循环中，但我仍然继续获取该值。

Answer 1

double *SSD = new double[R*C];

您已经分配了内存但从未将其初始化为某个值。那么你已经直接使用了:

SSD[R*C] += Compare[x][y];

在开始向其添加值之前，将 SSD 的所有项目初始化为 0。