Language: C++

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <string>
#include <cmath>
#include <stack>
#include <vector>
#include <iostream>
 
 
using namespace std;
 
int main()
{
    int n;
    scanf("%d", &n);
    for (int i = 0; i < n; ++i)
    {
        double x[4], y[4];
        for (int j = 0; j < 4; ++j)
            scanf("%lf %lf", x+j, y+j);
 
        double dx1 = x[1] - x[0];
        double dy1 = y[1] - y[0];
        double dx2 = x[3] - x[2];
        double dy2 = y[3] - y[2];
        if (dy1/dx1 == dy2/dx2)
            puts("YES");
        else
            puts("NO");
    }
 
    return 0;
}


Compiler output:
a.cc:9:1: error: extended character   is not valid in an identifier
    9 |  
      | ^
a.cc:10:1: error: extended character   is not valid in an identifier
   10 |  
      | ^
a.cc:12:1: error: extended character   is not valid in an identifier
   12 |  
      | ^
a.cc:15:1: error: extended character   is not valid in an identifier
   15 |     int n;
      | ^
a.cc:15:1: error: extended character   is not valid in an identifier
a.cc:15:1: error: extended character   is not valid in an identifier
a.cc:15:1: error: extended character   is not valid in an identifier
a.cc:16:1: error: extended character   is not valid in an identifier
   16 |     scanf("%d", &n);
      | ^
a.cc:16:1: error: extended character   is not valid in an identifier
a.cc:16:1: error: extended character   is not valid in an identifier
a.cc:16:1: error: extended character   is not valid in an identifier
a.cc:17:1: error: extended character   is not valid in an identifier
   17 |     for (int i = 0; i < n; ++i)
      | ^
a.cc:17:1: error: extended character   is not valid in an identifier
a.cc:17:1: error: extended character   is not valid in an identifier
a.cc:17:1: error: extended character   is not valid in an identifier
a.cc:18:1: error: extended character   is not valid in an identifier
   18 |     {
      | ^
a.cc:18:1: error: extended character   is not valid in an identifier
a.cc:18:1: error: extended character   is not valid in an identifier
a.cc:18:1: error: extended character   is not valid in an identifier
a.cc:19:1: error: extended character   is not valid in an identifier
   19 |         double x[4], y[4];
      | ^
a.cc:19:1: error: extended character   is not valid in an identifier
a.cc:19:1: error: extended character   is not valid in an identifier
a.cc:19:1: error: extended character   is not valid in an identifier
a.cc:19:1: error: extended character   is not valid in an identifier
a.cc:19:1: error: extended character   is not valid in an identifier
a.cc:19:1: error: extended character   is not valid in an identifier
a.cc:19:1: error: extended character   is not valid in an identifier
a.cc:20:1: error: extended character   is not valid in an identifier
   20 |         for (int j = 0; j < 4; ++j)
      | ^
a.cc:20:1: error: extended character   is not valid in an identifier
a.cc:20:1: error: extended character   is not valid in an identifier
a.cc:20:1: error: extended character   is not valid in an identifier
a.cc:20:1: error: extended character   is not valid in an identifier
a.cc:20:1: error: extended character   is not valid in an identifier
a.cc:20:1: error: extended character   is not valid in an identifier
a.cc:20:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
   21 |             scanf("%lf %lf", x+j, y+j);
      | ^
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:21:1: error: extended character   is not valid in an identifier
a.cc:22:1: error: extended character   is not valid in an identifier
   22 |  
      | ^
a.cc:23:1: error: extended character   is not valid in an identifier
   23 |         double dx1 = x[1] - x[0];
      | ^
a.cc:23:1: error: extended character   is not valid in an identifier
a.cc:23:1: error: extended character   is not valid in an identifier
a.cc:23:1: error: extended character   is not valid in an identifier
a.cc:23:1: error: extended character   is not valid in an identifier
a.cc:23:1: error: extended character   is not valid in an identifier
a.cc:23:1: error: extended character   is not valid in an identifier
a.cc:23:1: error: extended character   is not valid in an identifier
a.cc:24:1: error: extended character   is not valid in an identifier
   24 |         double dy1 = y[1] - y[0];
      | ^
a.cc:24:1: error: extended character   is not valid in an identifier
a.cc:24:1: error: extended character   is not valid in an identifier
a.cc:24:1: error: extended character   is not valid in an identifier
a.cc:24:1: error: extended character   is not valid in an identifier
a.cc:24:1: error: extended character   is not valid in an identifier
a.cc:24:1: error: extended character   is not valid in an identifier
a.cc:24:1: error: extended character   is not valid in an identifier
a.cc:25:1: error: extended character   is not valid in an identifier
   25 |         double dx2 = x[3] - x[2];
      | ^
a.cc:25:1: error: extended character   is not valid in an identifier
a.cc:25:1: error: extended character   is not valid in an identifier
a.cc:25:1: error: extended character   is not valid in an identifier
a.cc:25:1: error: extended character   is not valid in an identifier
a.cc:25:1: error: extended character   is not valid in an identifier
a.cc:25:1: error: extended character   is not valid in an identifier
a.cc:25:1: error: extended character   is not valid in an identifier
a.cc:26:1: error: extended character   is not valid in an identifier
   26 |         double dy2 = y[3] - y[2];
      | ^
a.cc:26:1: error: extended character   is not valid in an identifier
a.cc:26:1: error: extended character   is not valid in an identifier
a.cc:26:1: error: extended character   is not valid in an identifier
a.cc:26:1: error: extended character   is not valid in an identifier
a.cc:26:1: error: extended character   is not valid in an identifier
a.cc:26:1: error: extended character   is not valid in an identifier
a.cc:26:1: error: extended character   is not valid in an identifier
a.cc:27:1: error: extended character   is not valid in an identifier
   27 |         if (dy1/dx1 == dy2/dx2)
      | ^
a.cc:27:1: error: extended character   is not valid in an identifier
a.cc:27:1: error: extended character   is not valid in an identifier
a.cc:27:1: error: extended character   is not valid in an identifier
a.cc:27:1: error: extended character   is not valid in an identifier
a.cc:27:1: error: extended character   is not valid in an identifier
a.cc:27:1: error: extended character   is not valid in an identifier
a.cc:27:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
   28 |             puts("YES");
      | ^
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:28:1: error: extended character   is not valid in an identifier
a.cc:29:1: error: extended character   is not valid in an identifier
   29 |         else
      | ^
a.cc:29:1: error: extended character   is not valid in an identifier
a.cc:29:1: error: extended character   is not valid in an identifier
a.cc:29:1: error: extended character   is not valid in an identifier
a.cc:29:1: error: extended character   is not valid in an identifier
a.cc:29:1: error: extended character   is not valid in an identifier
a.cc:29:1: error: extended character   is not valid in an identifier
a.cc:29:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
   30 |             puts("NO");
      | ^
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:30:1: error: extended character   is not valid in an identifier
a.cc:31:1: error: extended character   is not valid in an identifier
   31 |     }
      | ^
a.cc:31:1: error: extended character   is not valid in an identifier
a.cc:31:1: error: extended character   is not valid in an identifier
a.cc:31:1: error: extended character   is not valid in an identifier
a.cc:32:1: error: extended character   is not valid in an identifier
   32 |  
      | ^
a.cc:33:1: error: extended character   is not valid in an identifier
   33 |     return 0;
      | ^
a.cc:33:1: error: extended character   is not valid in an identifier
a.cc:33:1: error: extended character   is not valid in an identifier
a.cc:33:1: error: extended character   is not valid in an identifier
a.cc:9:1: error: '\U000000a0' does not name a type
    9 |  
      | ^
a.cc:12:1: error: '\U000000a0' does not name a type
   12 |  
      | ^