Merge pull request #196 from pedroulissespu/master

Radial Sort Code in C+

Author: Shubhamlmp

C++/radial_sort.cpp

@@ -0,0 +1,48 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define type int
+#define point pair<type, type>
+#define X first
+#define Y second
+ 
+point operator-(point a, point b)
+{
+    return {a.X - b.X, a.Y - b.Y};
+}
+ 
+type operator*(point a, point b)
+{
+    return a.X * b.Y - a.Y * b.X;
+}
+ 
+int n;
+vector<point> P;
+point R;
+ 
+int dist(point a, point b)
+{
+    return (a.X - b.X) * (a.X - b.X) + (a.Y - b.Y) * (a.Y - b.Y); 
+}
+ 
+bool cmp(point a, point b)
+{
+    if((a - R).Y * (b - R).Y <= 0) return a.Y > R.Y;
+    int c = (a - R) * (b - R);
+    if(c == 0) return dist(R, a) <= dist(R, b);
+    return c > 0;
+}
+ 
+int main()
+{   
+    cin >> n >> R.X >> R.Y;
+    for(int i = 0; i < n; i++)
+    {
+        type x, y;
+        cin >> x >> y;
+        P.push_back({x, y});
+    }
+    sort(P.begin(), P.end(), cmp);
+    for(point p : P) cout << p.X << ' ' << p.Y << '\n';
+ 
+    return 0;
+}