C++ 片段

</pre><pre code_snippet_id="1563821" snippet_file_name="blog_20160124_1_1082829" name="code" class="cpp">#include <iostream>#include "opencv2/highgui/highgui.hpp"#include "opencv2/imgproc/imgproc.hpp"#include <string>#include <stdio.h>#include <map>#define pi 3.141592654using namespace std;using namespace cv;vector <Point> arr;vector <double> angle;Point scal;int n = 0; void create(){int x, y;while (cin >> x >>y){scal.x = x;scal.y = y;arr.push_back(scal);}for (vector<Point>::iterator it = arr.begin(); it != arr.end(); it++)cout << *it << endl;}void cal_angle(){ map<double, size_t> scalnum;for (int n = 0; n < arr.size(); n++)   angle.push_back(180*atan(arr[n].y/arr[n].x)/pi);sort(angle.begin(), angle.end());for (vector<double>::iterator it = angle.begin(); it != angle.end(); it++){cout << *it << endl;scalnum[*it] = n;n++;}for (const auto &s : scalnum){cout << s.first << " is  " << s.second << endl;}}int main(){    create();cal_angle();return 0;}

在计算坐标的时候，需要算出角度，以上是个实现的简单例子。