平面向量加法

https://pintia.cn/problem-sets/12/problems/345

解决舍入问题。

#include <stdio.h>
#include <math.h>

int main(void)
{
    struct p
    {
        double x;
        double y;
    };
    double x, y;

    struct p p1, p2;
    scanf("%lf %lf %lf %lf", &p1.x, &p1.y, &p2.x, &p2.y);

    x = p1.x + p2.x;
    y = p1.y + p2.y;

    if (fabs(x) < 0.05)
    {
        x = 0;
    }
    if (fabs(y) < 0.05)
    {
        y = 0;
    }

    printf("(%.1f, %.1f)", x, y);
    return 0;
}