#include<stdio.h>
#include<string.h>
#include<math.h>
double  INF;

double  ll;
double  find(double len)
{
    double r = INF, l = 0;
    double  mid, tmp;
    int  i;
    //while(fabs(r-l) > 1e-12)
    for(i = 0; i < 100; i++)
    {
        mid = (l+r)/2;
        tmp = 2*mid*asin(len/2/mid);
		//printf("%lf\n", tmp);
        if(fabs(tmp-ll) < 1e-12) return  mid;
        else  if(tmp < ll)
            r = mid;
        else  l = mid;
    }
	return 0;
}


int  main()
{
    double l, t, c;
    double  tmp;
	INF = 400000000;
	INF *= INF;
    while(scanf("%lf %lf %lf", &l, &t, &c) != EOF && fabs(l+1) > 1e-12)
    {
        if(fabs(l) < 1e-12){ printf("0.000\n"); continue; }
        ll = (1+t*c)*l;
		tmp = find(l);
        printf("%.3lf\n", tmp-sqrt(tmp*tmp-l*l/4));
    }
    return 0;
}

• UP~ (916) B06350214 2008-08-18 19:44:20
  • Re:UP~ (9) fireliuyu 2009-04-30 19:56:54
  • Re:UP~ (53) qiuzhenguang 2010-05-01 19:49:41
    • msG++浮点数输出要用%.f而不是%.lf的 (0) charmander 2010-05-01 22:12:15
      • Re:msG++浮点数输出要用%.f而不是%.lf的 (8) ice_of_shadow 2010-08-14 21:14:24
• Re:崩溃（G++死活不过）谁知道问题出在哪里？？！！ (927) 20071002871 2009-05-29 16:55:57