Codeforces beta round #2 C. COMMENTATOR Problem

Simulated annealing is really a very high-end thing. The idea is completely incomprehensible ~

Question:

Give three circles, and find that the two tangent angles from one point to the three circles are equal.

Solution:

There are many ideas for this question, but I cannot understand it ~~ /Shy face

Simulated annealing is also a bet, because the annealing process is not properly designed.

Actually, I learned a little bit. It's not very clear ~~

The following code is used:

# Include <set> # include <map> # include <queue> # include <math. h> # include <vector> # include <string> # include <stdio. h> # include <string. h> # include <stdlib. h> # include <iostream> # include <cctype> # include <algorithm> # define EPS 1e-6 # define PI ACOs (-1.0) # define INF 107374182 # define inf64 1152921504606846976 # define lc l, M, TR <1 # define RC m + 1, R, TR <1 | 1 # define zero () FABS (a) <EPS # define iabs (x)> 0? (X):-(x) # define clear1 (A, X, size) memset (A, X, sizeof (A [0]) * (min (size, sizeof (A) # define clearall (A, x) memset (A, X, sizeof (A) # define memcopy1 (A, X, size) memcpy (, x, sizeof (X [0]) * (size) # define memcopyall (A, x) memcpy (A, X, sizeof (x) # define max (X, y) (x)> (y ))? (X): (y) # define min (x, y) (x) <(y ))? (X): (y) using namespace STD; int dir [4] [2] ={{}, {-}, {}, {0, -1 }}; struct circle {Double X, Y, R;} CIR [3]; double DIS (Double X, Double Y, double XX, double YY) {return SQRT (x-xx) * (x-xx) + (Y-yy) * (Y-yy);} double F (Double X, Double Y) {double TMP [3]; for (INT I = 0; I <3; I ++) TMP [I] = DIS (X, Y, CIR [I]. x, CIR [I]. y)/CIR [I]. r; // The Sin value half of the angle of view is double ans = 0; For (INT I = 0; I <3; I ++) ans + = (TMP [I]-TMP [(I + 1) % 3]) * (TMP [I]-TMP [(I + 1) % 3]); return ans;} int main () {Double X = 0, y = 0; For (INT I = 0; I <3; I ++) {scanf ("% lf", & CIR [I]. x, & CIR [I]. y, & CIR [I]. r); x + = CIR [I]. x/3; y + = CIR [I]. y/3;} double step = 2; while (Step> EPS) {double TMP = f (x, y); int tag =-1; for (INT I = 0; I <4; I ++) {double CNT = f (x + dir [I] [0] * step, Y + dir [I] [1] * step ); if (CNT <TMP) {TMP = CNT; tag = I ;}} if (TAG =-1) STEP/= 2; else {x = x + dir [tag] [0] * step; y = Y + dir [tag] [1] * Step ;}} if (f (x, y) <EPS) printf ("%. 5lf %. 5lf \ n ", x, y); Return 0 ;}

Codeforces beta round #2 C. COMMENTATOR Problem