• <ins id="pjuwb"></ins>
    <blockquote id="pjuwb"><pre id="pjuwb"></pre></blockquote>
    <noscript id="pjuwb"></noscript>
          <sup id="pjuwb"><pre id="pjuwb"></pre></sup>
            <dd id="pjuwb"></dd>
            <abbr id="pjuwb"></abbr>

            acm zoj1090解題報(bào)告

            Posted on 2010-09-19 22:44 李東亮 閱讀(1510) 評(píng)論(0)  編輯 收藏 引用
             

            The Circumference of the Circle

            本題在ZOJ上題號(hào)是1090,在POJ上是2242。題目描述如下:

            Description

            To calculate the circumference of a circle seems to be an easy task - provided you know its diameter. But what if you don't?

            You are given the cartesian coordinates of three non-collinear points in the plane.
            Your job is to calculate the circumference of the unique circle that intersects all three points.

            Input

            The input will contain one or more test cases. Each test case consists of one line containing six real numbers x1,y1, x2,y2,x3,y3, representing the coordinates of the three points. The diameter of the circle determined by the three points will never exceed a million. Input is terminated by end of file.

            Output

            For each test case, print one line containing one real number telling the circumference of the circle determined by the three points. The circumference is to be printed accurately rounded to two decimals. The value of pi is approximately 3.141592653589793.

            Sample Input

            0.0 -0.5 0.5 0.0 0.0 0.5

            0.0 0.0 0.0 1.0 1.0 1.0

            5.0 5.0 5.0 7.0 4.0 6.0

            0.0 0.0 -1.0 7.0 7.0 7.0

            50.0 50.0 50.0 70.0 40.0 60.0

            0.0 0.0 10.0 0.0 20.0 1.0

            0.0 -500000.0 500000.0 0.0 0.0 500000.0

            Sample Output

            3.14

            4.44

            6.28

            31.42

            62.83

            632.24

            3141592.65

            分析:本題是一道比較容易的題,具體就考察了幾個(gè)數(shù)學(xué)公式的使用。本題的關(guān)鍵是求出內(nèi)接三角形的外接圓直徑。而在圓的內(nèi)接三角形的性質(zhì)中有這樣一條:三角形的任何兩邊的乘積的等于第三邊上的高于其外接圓直徑的乘積。這樣問題就轉(zhuǎn)化為求接三角形的某一邊上的高,在知道三角形三個(gè)頂點(diǎn)的情況下,求其面積應(yīng)該是件容易事,求得面積后,高的問題也就迎刃而解。求面積時(shí),由于本人較懶,用的是海倫公式:S = ,其中p = (a+b+c)/2abc分別為三角形的三個(gè)變長(zhǎng),S=0.5*c*h,即可求得ha*b=h*d,那么直徑d也就出來了。具體代碼如下.

            #include <stdio.h>

            #include <stdlib.h>

            #include <math.h>

            int main(void)

            {

                   double x1, y1, x2, y2, x3, y3;

                   double l1, l2, l3;

                   double p;

                   double h;

                   double d;

                   while (scanf("%lf%lf%lf%lf%lf%lf", &x1, &y1, &x2, &y2, &x3, &y3) == 6)

                   {

                          l1 = sqrt(pow(x1-x2, 2) + pow(y1-y2, 2));

                          l2 = sqrt(pow(x1-x3, 2) + pow(y1-y3, 2));

                          l3 = sqrt(pow(x2-x3, 2) + pow(y2-y3, 2));

                          p = (l1 + l2 + l3)/2;

                          h = sqrt(p*(p-l1)*(p-l2)*(p-l3))*2/l3;

                          d = l1*l2/h;

                          printf("%.2f\n", 3.141592653589793*d);

                   }

                   return 0;

            }


            只有注冊(cè)用戶登錄后才能發(fā)表評(píng)論。
            網(wǎng)站導(dǎo)航: 博客園   IT新聞   BlogJava   博問   Chat2DB   管理


            posts - 12, comments - 1, trackbacks - 0, articles - 1

            Copyright © 李東亮

            久久99精品九九九久久婷婷 | 狠狠精品干练久久久无码中文字幕| 国产精品亚洲综合久久 | 精品久久一区二区| 亚洲色欲久久久久综合网| 久久婷婷五月综合成人D啪| 亚洲午夜精品久久久久久app| 久久久久久免费视频| 久久精品人人做人人爽电影蜜月| 久久精品国产只有精品2020| 久久综合视频网站| 狠狠色丁香久久婷婷综合五月 | 亚洲国产成人精品91久久久 | 91精品国产综合久久久久久| 久久久精品波多野结衣| 少妇高潮惨叫久久久久久| 久久久久国产精品| 久久人人爽人人人人爽AV| www性久久久com| 国产成人无码精品久久久性色| 一级做a爰片久久毛片人呢| 日韩久久久久久中文人妻| 欧美激情精品久久久久久久九九九 | 国产精品久久久久9999| 久久天天婷婷五月俺也去| 91久久精品国产成人久久| 久久综合狠狠综合久久综合88 | 99久久成人18免费网站| 欧美一区二区三区久久综合| 欧美亚洲国产精品久久久久| 国产2021久久精品| 国产精品久久久久久久久鸭| 久久99精品久久只有精品| 久久久亚洲欧洲日产国码是AV| 欧美日韩精品久久久久| 国产精品美女久久久久AV福利| 久久综合丁香激情久久| 久久亚洲精品视频| 99久久国产综合精品网成人影院| 99久久婷婷国产一区二区| 51久久夜色精品国产|