From a305ed188e9601a5432aebeb7759cae549d3b22e Mon Sep 17 00:00:00 2001
From: Rohan Sharma <50175798+Rohanfizz@users.noreply.github.com>
Date: Sun, 24 Oct 2021 11:32:27 +0530
Subject: [PATCH 1/2] Create Point_Location_Test.cpp

---
 .../Point_Location_Test.cpp                   | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 Algorithms/Geometry-Algorithms/Point_Location_Test.cpp

diff --git a/Algorithms/Geometry-Algorithms/Point_Location_Test.cpp b/Algorithms/Geometry-Algorithms/Point_Location_Test.cpp
new file mode 100644
index 0000000..02be8c2
--- /dev/null
+++ b/Algorithms/Geometry-Algorithms/Point_Location_Test.cpp
@@ -0,0 +1,20 @@
+//https://cses.fi/problemset/task/2189
+#include <bits/stdc++.h>
+using namespace std;
+ 
+int main(){
+    ios::sync_with_stdio(0); cin.tie(0);
+    int T; cin>>T;
+    while(T--){
+        long x1,y1,x2,y2,x3,y3;
+        cin>>x1>>y1>>x2>>y2>>x3>>y3;
+        
+        long val = (x3-x2)*(y2-y1) - (x2-x1)*(y3-y2);
+        if(val>0){ // clockwise
+            cout<<"RIGHT"<<endl;
+        }else if(val<0){
+            cout<<"LEFT"<<endl;
+        }else cout<<"TOUCH"<<endl;
+ 
+    }
+}

From 61d3ca1958a5f5ff12c4a0c6377722a3ef7c37f5 Mon Sep 17 00:00:00 2001
From: Rohan Sharma <50175798+Rohanfizz@users.noreply.github.com>
Date: Sun, 24 Oct 2021 12:13:35 +0530
Subject: [PATCH 2/2] Create Line-Segment-Intersection.cpp

---
 .../Line-Segment-Intersection.cpp             | 121 ++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 Algorithms/Geometry-Algorithms/Line-Segment-Intersection.cpp

diff --git a/Algorithms/Geometry-Algorithms/Line-Segment-Intersection.cpp b/Algorithms/Geometry-Algorithms/Line-Segment-Intersection.cpp
new file mode 100644
index 0000000..80252e7
--- /dev/null
+++ b/Algorithms/Geometry-Algorithms/Line-Segment-Intersection.cpp
@@ -0,0 +1,121 @@
+// https://cses.fi/problemset/task/2190
+
+/*
+ Code by,
+ ___     _               __ _       
+| _ \___| |_  __ _ _ _  / _(_)______
+|   / _ \ ' \/ _` | ' \|  _| |_ /_ /
+|_|_\___/_||_\__,_|_||_|_| |_/__/__|                                                       
+*/
+#include<bits/stdc++.h>
+typedef int int32_t;
+#define int         long long int
+#define LOOP(i,n)   for (int i = 1; i <= n; i++)
+#define loop(i,n)   for(int i = 0;i<n;i++)
+#define REP(i,a,b)  for(int i = a;i<=b;i++)
+#define INF         1000000000
+#define mod         1000000007
+#define pb          push_back
+#define ff          first
+#define ss          second
+#define ii          pair<int,int>
+#define vi          vector<int>
+#define vvi         vector<vi>
+#define vii         vector<ii>
+ 
+#define szv(V)      ((int)(V).size())
+#define allv(V)     (V).begin(), (V).end()
+#define sortv(V)    sort(allv(V));
+#define debug       cout<<"debugged here"<<endl;
+ 
+#define endl        '\n'
+#define X           real()
+#define Y           imag()
+#define tup         tuple<int,int,int>
+#define graphType   vector<vector<tup>>
+#define zt(x)       get<0>(x)
+#define ot(x)       get<1>(x)
+#define tt(x)       get<2>(x)
+//oprations
+#define isPowerOf2(x) (x && ceil(log2(x))==floor(log2(x)))
+#define dotp(a,b)   ( (conj(a)*(b)).real() )	// a*b cos(T), if zero -> prep
+#define crossp(a,b) ( (conj(a)*(b)).imag() )	// a*b sin(T), if zero -> parllel
+#define firstSetBit(n) ( (log2(n & -n) + 1)   )
+//
+const double EPS = (1e-7);
+const double PI = 3.141592653589793238460;
+typedef std::complex<double> point;
+typedef std::valarray<point> CArray;
+    
+using namespace std;
+int __lcm(int a,int b) {return a*b/__gcd(a,b);}
+int dcmp(double x, double y) {	return fabs(x-y) <= EPS ? 0 : x < y ? -1 : 1;	}
+ 
+struct hash_pair { 
+    template <class T1, class T2> 
+    size_t operator()(const pair<T1, T2>& p) const{ 
+        auto hash1 = hash<T1>{}(p.first); 
+        auto hash2 = hash<T2>{}(p.second); 
+        return hash1 ^ hash2; 
+    } 
+}; 
+ 
+void addEdge(graphType& graph, int src, int nbr, int wt){
+    graph[src].pb(make_tuple(src,nbr,wt));
+}
+ 
+void addEdge2(graphType& graph, int src, int nbr, int wt){
+    graph[src].pb(make_tuple(src,nbr,wt));
+    graph[nbr].pb(make_tuple(nbr,src,wt));
+}
+ 
+graphType graphDefine(int sz){
+    graphType graph;
+    for(int i = 0;i<sz;i++){
+        vector<tup> t; 
+        graph.pb(t);
+    }
+    return graph;
+}
+ 
+int ori(int x1,int y1,int x2,int y2,int x3,int y3){
+    int val = (x3-x2)*(y2-y1) - (x2-x1)*(y3-y2);
+    if(val>0) return 1; // clockwise
+    else if(val<0) return 2; // counter-clockwise
+    return 0; //collinear
+}
+ 
+bool onSeg(int x1,int y1,int x2,int y2,int x3,int y3){
+    return (x3<=max(x1,x2) && x3>=min(x1,x2) && y3<=max(y1,y2) && y3>=min(y1,y2));
+}
+int32_t main(){
+    ios::sync_with_stdio(0); cin.tie(0);
+    // freopen("input.txt", "r", stdin);
+    // freopen("output.txt", "w", stdout);
+    int T; cin>>T;
+    while(T--){
+        int x1,y1,x2,y2,x3,y3,x4,y4; cin>>x1>>y1>>x2>>y2>>x3>>y3>>x4>>y4;
+        int o1 = ori(x1,y1,x2,y2,x3,y3);
+        int o2 = ori(x1,y1,x2,y2,x4,y4);
+        int o3 = ori(x3,y3,x4,y4,x1,y1);
+        int o4 = ori(x3,y3,x4,y4,x2,y2);
+        if( o1!=o2  && o3!=o4 ){
+            cout<<"YES"<<endl;
+        }else if(o1 == 0 && onSeg(x1,y1,x2,y2,x3,y3)){      
+            cout<<"YES"<<endl;
+        }else if(o2 == 0 && onSeg(x1,y1,x2,y2,x4,y4)){
+            cout<<"YES"<<endl;
+        }else if(o3 == 0 && onSeg(x3,y3,x4,y4,x1,y1)){
+            cout<<"YES"<<endl;
+        }else if(o4 == 0 && onSeg(x3,y3,x4,y4,x2,y2)){
+            cout<<"YES"<<endl;
+        }else cout<<"NO"<<endl;
+    }
+}
+/* 
+Checks
+-> provided test cases
+-> integer overflow,array bounds
+-> special cases (n==1?)
+-> copy all used functions
+*/