B. Amr and Pins time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Amr loves Geometry. One day he came up with a very interesting problem. Amr has a circle of radius r and center in point (x, …

Amr loves Geometry. One day he came up with a very interesting problem. Amr has a circle of radius r and center in point (x, y). He wants the circle center to be in new position (x', y'). In one step Amr can put a pin to the border of the circle in a…

Amr loves Geometry. One day he came up with a very interesting problem. Amr has a circle of radius r and center in point (x, y). He wants the circle center to be in new position (x', y'). In one step Amr can put a pin to the border of the circle in a…

题目链接:http://codeforces.com/problemset/problem/507/B 题目意思:给出圆的半径,以及圆心坐标和最终圆心要到达的坐标位置.问最少步数是多少.移动见下图.(通过圆上的边固定转动点,然后转动任意位置,圆心就会移动了,这个还是直接看图吧) 解题的思路就是,两点之间,距离最短啦----要想得到最少步数,我们需要保证圆心在这条连线上移动,每次转动的角度是180度,而每步移动的距离是2r,直到两个圆交叉,要注意最后一步转动的角度可能会小于180度.最后就是注意精…

Amr and Pins time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Amr loves Geometry. One day he came up with a very interesting problem. Amr has a circle of radius r and center in point (x, y).…

B. Amr and Pins time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Amr loves Geometry. One day he came up with a very interesting problem. Amr has a circle of radius r and center in point (x, …

B. Amr and Pins time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Amr loves Geometry. One day he came up with a very interesting problem. Amr has a circle of radius r and center in point (x, …

解题思路:一开始自己想的是找出每一次旋转所得到的圆心轨迹,将想要旋转到的点代入该圆心轨迹的方程,如果相等,则跳出循环,如果不相等,则接着进行下一次旋转.后来看了题解,发现,它的旋转可以是任意角度的,所以旋转后的圆心应该在一个区域,而没有固定的圆心轨迹的方程. 如图所示,设c0为最初给出的圆,令圆c0绕O1点旋转,则对于绕O1点这一点的旋转来说,c1为其旋转后所得到的圆心轨迹,则可以看到,通过1次旋转后,距离最近为0,距离最远为线段OO2=2r, 对于第二次旋转,选取O2为圆心,作圆,再令圆c2绕…

A. Amr and Music (贪心) 水题,没能秒切,略尴尬. #include <cstdio> #include <algorithm> using namespace std; +; int a[maxn], r[maxn], ans[maxn]; int cmp(int i, int j) { return a[i] < a[j]; } int main() { //freopen("in.txt", "r", stdin…

音频转换: 1.转换amr到mp3: ffmpeg -i shenhuxi.amr amr2mp3.mp3 2.转换amr到wav: ffmpeg -acodec libamr_nb -i shenhuxi.amr amr2wav.wav 3.转换mp3到wav: ffmpeg -i DING.mp3 -f wav test.wav 4.转换wav到amr: ffmpeg -i test.wav -acodec libamr_nb -ab .2k - -ac wav2amr.amr ffmpeg…