编程 输入一平面坐标点(x,y),判断并输出该坐标点位于哪个象限?c语言

Posted 2023-04-21

参考技术A #include<stdio.h>

int x,y;
char *output[20];
int p;

void main()
printf("请输入一个坐标如：3,3\n");
while(scanf("%d,%d",&x,&y)!=EOF)


if(x > 0 && y > 0)
p=1;
else if(x > 0 && y < 0)
p=4;
else if(x < 0 && y > 0)
p=2;
else if(x < 0 && y < 0)
p=3;

switch(p)
case 1:*output = "第一象限\n";break;
case 4:*output = "第四象限\n";break;
case 2:*output = "第二象限\n";break;
case 3:*output = "第三象限\n";break;

printf("%s",*output);

本回答被提问者采纳 参考技术B typedef enum tag_epos

FIRST = 1,
SECOND,
THIRD,
FOURTH,
EPOS;

int getPos(int x, int y)

if( (x > 0) && (y > 0))

return FIRST;

else if( (x < 0) && (y > 0))

return SECOND;

else if( (x < 0) && (y < 0))

return THIRD;

else if( (x > 0) && (y < 0))

return FOURTH;

else

return -1;



int main()

int x = 10, y = 10;
// int x = 10, y = -10;
int pos = getPos(x,y);

switch(pos)

case FIRST:
printf("FIRST\r\n"); break;
case SECOND:
printf("SECOND\r\n"); break;
case THIRD:
printf("THIRD\r\n"); break;
case FOURTH:
printf("FOURTH\r\n"); break;
default:
printf("Error\r\n");


return 0;


Output:
FIRST

php实现 计算坐标点在某区域

项目需求:通过地图坐标和区域坐标点集合 判断当前坐标是否在坐标点集合区域中
$area[array] 区域坐标点集合数组

$area = array(
　　// 天通苑店
　　0 => array(
　　　　array(‘x‘=>116.38295, ‘y‘=>40.09416),
　　　　array(‘x‘=>116.44037, ‘y‘=>40.095898),
　　　　array(‘x‘=>116.448275,‘y‘=>40.083313),
　　　　array(‘x‘=>116.448455,‘y‘=>40.050818),
　　　　array(‘x‘=>116.448275,‘y‘=>40.038307),
　　　　array(‘x‘=>116.441448,‘y‘=>40.038418),
　　　　array(‘x‘=>116.436058,‘y‘=>40.038804),
　　　　array(‘x‘=>116.417302,‘y‘=>40.039136),
　　　　array(‘x‘=>116.414822,‘y‘=>40.039384),
　　　　array(‘x‘=>116.412738,‘y‘=>40.039329),
　　　　array(‘x‘=>116.407672,‘y‘=>40.039329),
　　　　array(‘x‘=>116.388628,‘y‘=>40.085162),
　　　　array(‘x‘=>116.383633,‘y‘=>40.084997)
　　),
　　//亚运村
　　1 => array(
　　　　array(‘x‘=>116.358804,‘y‘=>40.028474),
　　　　array(‘x‘=>116.41608, ‘y‘=>40.02875),
　　　　array(‘x‘=>116.41723, ‘y‘=>40.038915),
　　　　array(‘x‘=>116.447988,‘y‘=>40.037921),
　　　　array(‘x‘=>116.447844,‘y‘=>40.026761),
　　　　array(‘x‘=>116.455821,‘y‘=>40.024164),
　　　　array(‘x‘=>116.446281,‘y‘=>39.994736),
　　　　array(‘x‘=>116.443532,‘y‘=>39.995372),
　　　　array(‘x‘=>116.376267,‘y‘=>39.993493),
　　　　array(‘x‘=>116.375908,‘y‘=>40.000015),
　　　　array(‘x‘=>116.372027,‘y‘=>39.999904),
　　　　array(‘x‘=>116.371452,‘y‘=>40.007366),
　　　　array(‘x‘=>116.359451,‘y‘=>40.006758)
　　),
　　//望京店
　　2 => array(
　　　　array(‘x‘=>116.46387, ‘y‘=>40.021125),
　　　　array(‘x‘=>116.484495,‘y‘=>40.020462),
　　　　array(‘x‘=>116.515684,‘y‘=>39.995151),
　　　　array(‘x‘=>116.51519, ‘y‘=>39.976137),
　　　　array(‘x‘=>116.491906,‘y‘=>39.972985),
　　　　array(‘x‘=>116.476239,‘y‘=>39.977298),
　　　　array(‘x‘=>116.467472,‘y‘=>39.96917),
　　　　array(‘x‘=>116.443325,‘y‘=>39.984817),
　　　　array(‘x‘=>116.449506,‘y‘=>39.993109),
　　　　array(‘x‘=>116.446357,‘y‘=>39.994736),
　　　　array(‘x‘=>116.456037,‘y‘=>40.024109)
　　),
);

 

 

<?php
/**
 * 验证坐标点是否在某区域内
 * @author xiaoliang <[email protected]>
 * Class validationMap
 */
class InareaAction extends CommonAction {
    // 一个表示区域的三维数组
    public $config = null;

    // 包含每个区域的四边形
    public $rectangles = null;

    // 每个区域（多边形）的所有边
    public $lines = null;

    // 要判断的点的x, y坐标
    public $_x = null;
    public $_y = null;

    public function __construct($config){
        $this->config = $config;
        $this->initRectangles();
        $this->initLines();
    }

    /*
        获取包含每个配送区域的四边形
    */
    public function initRectangles(){
        foreach ($this->config as $k => $v) {
            $this->rectangles[$k][‘minX‘] = $this->getMinXInEachConfig($k);
            $this->rectangles[$k][‘minY‘] = $this->getMinYInEachConfig($k);
            $this->rectangles[$k][‘maxX‘] = $this->getMaxXInEachConfig($k);
            $this->rectangles[$k][‘maxY‘] = $this->getMaxYInEachConfig($k);
        }
    }

    /*
        初始化每个区域（多边形）的边（线段：直线的一部分【限制x或者y坐标范围】）
        n 个顶点构成的多边形，有 n-1 条边
    */
    public function initLines(){
        foreach ($this->config as $k => $v) {
            $pointNum = count($v);		// 区域的顶点个数
            $lineNum = $pointNum - 1; 	// 区域的边条数
            for($i=0; $i<$lineNum; $i++){
                // y=kx+b : k
                if($this->config[$k][$i][‘x‘] - $this->config[$k][$i+1][‘x‘] == 0) $this->lines[$k][$i][‘k‘] = 0;
                else $this->lines[$k][$i][‘k‘] =
                    ($this->config[$k][$i][‘y‘] - $this->config[$k][$i+1][‘y‘])/($this->config[$k][$i][‘x‘] - $this->config[$k][$i+1][‘x‘]);
                // y=kx+b : b
                $this->lines[$k][$i][‘b‘] = $this->config[$k][$i+1][‘y‘] - $this->lines[$k][$i][‘k‘] * $this->config[$k][$i+1][‘x‘];
                $this->lines[$k][$i][‘lx‘] = min($this->config[$k][$i][‘x‘], $this->config[$k][$i+1][‘x‘]);
                $this->lines[$k][$i][‘rx‘] = max($this->config[$k][$i][‘x‘], $this->config[$k][$i+1][‘x‘]);
            }
            $pointNum-=1;
            if($this->config[$k][$pointNum][‘x‘] - $this->config[$k][0][‘x‘] == 0) $this->lines[$k][$pointNum][‘k‘] = 0;
            else $this->lines[$k][$pointNum][‘k‘] =
                ($this->config[$k][$pointNum][‘y‘] - $this->config[$k][0][‘y‘])/($this->config[$k][$pointNum][‘x‘] - $this->config[$k][0][‘x‘]);
            // y=kx+b : b
            $this->lines[$k][$pointNum][‘b‘] = $this->config[$k][0][‘y‘] - $this->lines[$k][$pointNum][‘k‘] * $this->config[$k][0][‘x‘];
            $this->lines[$k][$pointNum][‘lx‘] = min($this->config[$k][$pointNum][‘x‘], $this->config[$k][0][‘x‘]);
            $this->lines[$k][$pointNum][‘rx‘] = max($this->config[$k][$pointNum][‘x‘], $this->config[$k][0][‘x‘]);
        }
    }

    /*
        获取一组坐标中，x坐标最小值
    */
    public function getMinXInEachConfig($index){
        $minX = 200;
        foreach ($this->config[$index] as $k => $v) {
            if($v[‘x‘] < $minX){
                $minX = $v[‘x‘];
            }
        }
        return $minX;
    }

    /*
        获取一组坐标中，y坐标最小值
    */
    public function getMinYInEachConfig($index){
        $minY = 200;
        foreach ($this->config[$index] as $k => $v) {
            if($v[‘y‘] < $minY){
                $minY = $v[‘y‘];
            }
        }
        return $minY;
    }

    /*
        获取一组坐标中，x坐标最大值
    */
    public function getMaxXInEachConfig($index){
        $maxX = 0;
        foreach ($this->config[$index] as $k => $v) {
            if($v[‘x‘] > $maxX){
                $maxX = $v[‘x‘];
            }
        }
        return $maxX;
    }

    /*
        获取一组坐标中，y坐标最大值
    */
    public function getMaxYInEachConfig($index){
        $maxY = 0;
        foreach ($this->config[$index] as $k => $v) {
            if($v[‘y‘] > $maxY){
                $maxY = $v[‘y‘];
            }
        }
        return $maxY;
    }

    /*
        获取 y=y0 与特定区域的所有边的交点，并去除和顶点重复的，再将交点分为左和右两部分
    */
    public function getCrossPointInCertainConfig($index){
        $crossPoint = null;
        foreach ($this->lines[$index] as $k => $v) {
            if($v[‘k‘] == 0) return true;
            $x0 = ($this->_y - $v[‘b‘]) / $v[‘k‘];	// 交点x坐标
            if($x0 == $this->_x) return true;		// 点在边上
            if($x0 > $v[‘lx‘] && $x0 < $v[‘rx‘]){
                if($x0 < $this->_x) $crossPoint[‘left‘][] = $x0;
                if($x0 > $this->_x) $crossPoint[‘right‘][] = $x0;
            }
        }
        return $crossPoint;
    }

    /*
        检测一个点，是否在区域内
        返回结果：
            return === false : 点不在区域内
            return 0, 1, 2, 3 ... 点所在的区域编号（配置文件中的区域编号。）
    */
    public function checkPoint($x, $y){
        $this->_x = $x;
        $this->_y = $y;
        $contain = null;
        foreach ($this->rectangles as $k => $v) {
            if($x > $v[‘maxX‘] || $x < $v[‘minX‘] || $y > $v[‘maxY‘] || $y < $v[‘minY‘]){
                continue;
            }else{
                $contain = $k;
                break;
            }
        }
        if($contain === null) return false;
        $crossPoint = $this->getCrossPointInCertainConfig($contain);
        if($crossPoint === true) return $contain;
        if(count($crossPoint[‘left‘])%2 == 1 && count($crossPoint[‘right‘])%2 == 1) return $contain;
        return false;
    }
}

//实例化对象
$area = new Area($area); 
//判断坐标点是否在区域中 如果坐标点在某一区域返回区域编号 否则返回false;
var_dump($area->checkPoint(116.531748,39.944229))