AOJ2233.cpp

#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <map>
#include <queue>
#include <algorithm>
#include <complex>

#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(x) (x).begin(),(x).end()

using namespace std;

typedef double ld;
typedef complex<ld> P;

const ld INF = 1e12;
const ld pi = acos(-1.0);
const int M = 13000;

ld dist[32][32][32];
ld dp[M][22][22];

int main() {
  int n;
  ld r, theta, x, y;
  cin >> n >> r >> theta;
  vector<P> p(n);
  REP(i,n) {
    cin >> x >> y;
    p[i] = P(x, y);
  }
  REP(i,n) REP(j,n) REP(k,n) dist[i][j][k] = INF;
  REP(i,n) REP(j,n) REP(k,n) {
    if (i == j || j == k) continue;
    P next = p[k] - p[j];
    P prev = p[j] - p[i];
    if (abs(arg(next / prev)) < theta / 180.0 * pi)
      dist[i][j][k] = abs(next);
  }
  
  REP(c,M) REP(i,n) REP(j,n) dp[c][i][j] = INF;
  for (int j = 1; j < n; j++)
    dp[0][0][j] = abs(p[0] - p[j]);
  int res = 0;
  REP(c,M-1) REP(i,n) REP(j,n) REP(k,n) {
    dp[c+1][j][k] = min(dp[c+1][j][k], dp[c][i][j] + dist[i][j][k]);
    if (dp[c][i][j] < r) res = c + 1;
  }
  cout << res << endl;
  return 0;
}