HDU 2348 Turn The corner (three points && geometry) (medium)

Turn the CornerTime limit:3000/1000 MS (java/others) Memory limit:32768/32768 K (java/others)
Total submission (s): 2229 Accepted Submission (s): 856


Problem descriptionmr. West bought a new car! So he's travelling around the city.

One day he comes to a vertical corner. The street he is currently in have a width x, the street he wants to turn to have a width y. The car has a length l and a width d.

Can Mr West go across the corner?

Inputevery line have four real numbers, X, Y, L and W.
Proceed to the end of file.

Outputif He can go across the corner, print "Yes". Print "No" otherwise.

Sample Input

10 6 13.5 410 6 14.5 4

Sample Output

Yesno

Test instructions

It is known that the length and width of the car, L and W, and the width of the two roads are X and Y, the car's road width is x, asking if the car can turn smoothly?

Analysis: Whether the car can smooth turn depends on the limit of the situation, with the change in angle, the car from the opposite side of the road is greater than or equal to 0

In

In the need to calculate whether the maximum value of H is less than or equal to Y during a turnobviously, with the increase of the angle θ, the maximum height of H first increases and then decreases, that is, the convex function, you can use the three-part method to solve

Code:

#include <iostream> #include <algorithm> #include <math.h> #include <cstdio>using namespace std ; #define PI 3.141592653double x,y,l,w;double cal (double A) {    double S=l*cos (a) +w*sin (a)-X;    Double H=s*tan (a) +w*cos (a);    return h;} int main () {    while (scanf ("%lf%lf%lf%lf", &x,&y,&l,&w)!=eof)    {        double left=0.0,right=pi /2;        Double lm,rm;        while (Fabs (right-left) >1e-6)        {            lm= (left*2.0+right)/3.0;            Rm= (left+right*2.0)/3.0;            if (Cal (LM) >cal (RM))                right=rm;            else left=lm;        }        if (Cal (left) <=y)            printf ("yes\n");        else printf ("no\n");    }    return 0;}

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HDU 2348 Turn The corner (three points && geometry) (medium)