A - Tick and Tick HDU - 1006

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A - Tick and Tick

  HDU - 1006 

The three hands of the clock are rotating every second and meeting each other many times everyday. Finally, they get bored of this and each of them would like to stay away from the other two. A hand is happy if it is at least D degrees from any of the rest. You are to calculate how much time in a day that all the hands are happy. 

InputThe input contains many test cases. Each of them has a single line with a real number D between 0 and 120, inclusively. The input is terminated with a D of -1. 
OutputFor each D, print in a single line the percentage of time in a day that all of the hands are happy, accurate up to 3 decimal places. 
Sample Input

0
120
90
-1

Sample Output

100.000
0.000
6.251

题意：时钟的三针厌倦了重叠的生活，他们觉得和另外两个保持一定的角度才会开心。给出角度，求一天中他们开心的时间占全天的百分比。

分析：原来想着一天不过43200秒，直接模拟就行了。结果怎么测数据都对不到，后来看了其他人的题解才知道这里的时间是连续的……

           但是只要计算单位足够小，暴力出答案还是没问题的（因为题解里解方程的代码看不懂_(:з」∠)_ ）

           最后以0.0001秒为单位时，AC（我的笔记本大概跑了9分钟吧……）

暴力代码：

#include<iostream>
#include<math.h>
#define e 0.00000001
using namespace std;
double num[121];
int main(){
	int n;
	double h=0,m=0,s=0;
	int cnt=0;
	for(int n=0;n<=120;n++){
		if(n==-1) return 0;
		h=0; m=0; s=0; cnt=0;
		while(360-h > e ){ 
			s+=0.0006; //1秒加6   以千分之一秒为单位
			m+=0.0006/60;
			h+=0.0006/60/12;
			if(s-360.0 >= 0) s=0.0;
			if(m-360.0 >= 0) m=0.0;
			double d1,d2,d3;
			d1=fabs(s-m);	d2=fabs(s-h);	d3=fabs(m-h);
			if(d1-180 > 0) d1=360.0-d1;
			if(d2-180 > 0) d2=360.0-d2;
			if(d3-180 > 0) d3=360.0-d3;
			if(d1-n>=0 && d2-n>=0 && d3-n>=0) cnt++;
		//	cout<<s<<" "<<m<<" "<<h<<" "<<cnt<<endl;
		}
		num[n] = (double)(cnt)*100/432000000; // 43200 * 1000
		cout<<num[n]<<endl;
	}
	for(int i=0;i<=120;i++)
		printf("%.3lf,",num[i]);
} 

提交代码：

#include<iostream>
using namespace std;
double num[121]={100.000,98.340,96.694,95.061,93.443,91.839,90.249,88.672,87.110,85.562
				,84.027,82.507,81.001,79.508,78.030,76.565,75.114,73.676,72.252,70.841
				,69.445,68.063,66.694,65.340,64.000,62.673,61.361,60.062,58.778,57.507
				,56.251,55.008,53.779,52.562,51.360,50.172,48.997,47.838,46.692,45.560
				,44.443,43.339,42.249,41.173,40.111,39.064,38.030,37.010,36.002,35.008
				,34.029,33.063,32.111,31.174,30.250,29.340,28.444,27.563,26.695,25.841
				,25.001,24.175,23.363,22.565,21.779,21.007,20.250,19.506,18.776,18.060
				,17.359,16.671,15.997,15.338,14.693,14.061,13.444,12.841,12.252,11.675
				,11.112,10.563,10.028,9.507,9.000,8.507,8.028,7.562,7.111,6.674,6.251,
				5.842,5.446,5.065,4.697,4.342,4.001,3.674,3.361,3.062,2.777,2.506,2.249
				,2.005,1.776,1.561,1.360,1.172,0.999,0.840,0.695,0.562,0.444,0.340,0.249
				,0.173,0.110,0.062,0.027,0.007,0.000};
int main(){
	int n;
	while(cin>>n){
		if(n==-1) return 0;
		else printf("%.3lf\n",num[n]);
	} 
}