50078. Parallelogram

#include <stdio.h>
#include <stdlib.h>

typedef struct{
    int x, y;
} s_pt;

s_pt add(s_pt a, s_pt b){
    s_pt rtv;
    rtv.x = a.x + b.x;
    rtv.y = a.y + b.y;
    return rtv;
}
s_pt minus(s_pt a, s_pt b){
    s_pt rtv;
    rtv.x = a.x - b.x;
    rtv.y = a.y - b.y;
    return rtv;
}

int main(){
    s_pt a, b, c;
    scanf("%d %d %d %d %d %d", &a.x, &a.y, &b.x, &b.y, &c.x, &c.y);
    s_pt d, e, f;

    d = add(minus(c, a), b);
    e = add(minus(c, b), a);
    f = add(minus(b, c), a);
    printf("%d\n%d\n%d\n%d\n%d\n%d\n", d.x, d.y, e.x, e.y, f.x, f.y);
}