Question

我正在尝试排序第一个向量向量l [0]是x1的点，然后它的长度总是改变

vector<int> v1;
v1.push_back(l[0]);
vector<int>::iterator Iter = v1.begin();
for (Iter = v1.begin(); Iter != v1.end(); Iter++){
sort(v1.begin(), v1.end());
cout << *Iter << endl;

它没有任何错误，但无法按顺序排序。我怎么解决呢？

编辑---------------------------------------------- ------------------------------

void thresh_callback(int, void*)
{

    /// Load source image and convert it to gray
    src = imread(img_file, 1);

    Mat threshold_output;
    Mat threshold_output1;
    Mat dst;
    vector<vector<Point> > contours;

    /// Detect edges using Threshold
    Canny(src_hist, threshold_output, thresh, thresh * 3, 3, false);
    Sharpen(threshold_output, threshold_output1);


    cvtColor(threshold_output1, dst, CV_GRAY2BGR);

    vector<Vec4i> lines;
    HoughLinesP(threshold_output1, lines, 1, CV_PI / 180, thresh1, min_line, max_gap);

    int erosion_size = 1;
    Mat element = getStructuringElement(MORPH_ERODE,
        Size(2 * erosion_size + 1, 2 * erosion_size + 1),
        Point(erosion_size, erosion_size));

    /// Apply the erosion operation
    dilate(dst, dst, element);

    imshow("Source", dst);

    for (size_t i = 0; i < lines.size(); i++)
    {
        Vec4i l = lines[i];
        Scalar color = Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255));
        int dx = l[2] - l[0];
        int dy = l[3] - l[1];

        double rad = atan2(dx, dy);
        double degree = (rad * 180) / M_PI;

        if (degree >= 180) degree -= 180;
        if (degree < 15 || degree > 165) {
            line(src, Point(l[0], l[1]), Point(l[2], l[3]), Scalar(0, 0, 255), 1, 8);
            //printf("%lf\n", degree);
            //printf("%d, %d, %d, %d, %d\n", l[0], l[1], l[2], l[3], i);

            vector<int> v1;
            v1.push_back(l[0]);
            vector<int>::iterator Iter = v1.begin();
            sort(v1.begin(), v1.end());
            for (Iter = v1.begin(); Iter != v1.end(); Iter++){
                cout << *Iter << endl;
            }
        }
        imshow("source", src);
    }

}

我使用houghline并找出x1，x2，y1，y2的点并得到每个x1和升序

Answer 1

不确定这是您的问题，但是......您在v1循环中定义for。

for (size_t i = 0; i < lines.size(); i++)
{
  // ...

        vector<int> v1;
        v1.push_back(l[0]);
        vector<int>::iterator Iter = v1.begin();
        sort(v1.begin(), v1.end());
        for (Iter = v1.begin(); Iter != v1.end(); Iter++){
            cout << *Iter << endl;
        }
  // ...
}

所以你，每次迭代，创建一个向量，插入一个元素，对向量进行排序（使用单个元素），打印单个值并销毁向量。

建议：在v1循环之外定义for。

---编辑---

正如aichao指出的那样，排序和打印部分可能在for循环之外更好;

之类的东西

vector<int> v1;

for (size_t i = 0; i < lines.size(); i++)
{
  // ...

        v1.push_back(l[0]);

  // ...
}

sort(v1.begin(), v1.end());

for ( vector<int>::const_iterator CIter = v1.cbegin(); CIter != v1.cend(); CIter++) {
   cout << *CIter << endl;
}

如果你可以编译C ++ 11或C ++ 14，那么最后一个for可以只是

for ( auto const & i : v1 )
   cout << i << endl;

p.s：抱歉我的英语不好。

c ++按升序顺序推送第一个向量和排序向量

1 个答案: