Answers for "two c-ordinate of square given how to find other two using c++"

two c-ordinate of square given how to find other two using c++

#include <cstdio>
#include <cmath>
#include <cstring>
#include <string>
#include <cstdlib>
#include <iostream>
#include <algorithm>
using namespace std;
const double eps = 1e-9;
#define INF 1e18
//typedef long long LL;
//typedef __int64 LL;
int main()
{
    int x1,x2,y1,y2;
    int x3,y3,x4,y4;

    while(~scanf("%d%d%d%d",&x1,&y1,&x2,&y2))
    {
        int t;
        if(x1 == x2 )
        {
            t = y1-y2;
            if(t < 0)
                t = -t;
            x3 = x1+t,x4 = x2+t;
            y3 = y1, y4 = y2;
            printf("%d %d %d %d\n",x3,y3,x4,y4);
            continue;
        }
        if(y1 == y2)
        {
            t = x1-x2;
            if(t < 0)
                t = -t;
            y3 = y1+t,y4 = y2+t;
            x3 = x1, x4 = x2;
            printf("%d %d %d %d\n",x3,y3,x4,y4);
            continue;
        }
       //if ((y2-y1) == (x2-x1))//slope 1
        if ((y2-y1) == (x2-x1) || (y2-y1) == - (x2-x1))//slope of 1 or -1
        {
            x3 = x1, y3 = y2;
            x4 = x2, y4 = y1;
            printf("%d %d %d %d\n",x3,y3,x4,y4);
            continue;
        }

        printf("-1\n");
    }
    return 0;
}