func_code_string: #include <bits/stdc++.h>   using namespace std;   void maximize(double &a, double b) { a = max(a, b); }   struct point {     long long int x, y;     point() {}     point(long long int x, long long int y) : x(x), y(y) {}   };   long long int prodesc(point p1, point p2) { return p1.x * p2.x + p1.y * p2.y; }   long long int prodvec(point p1, point p2) { return p1.x * p2.y - p1.y * p2.x; }   point operator-(point p1, point p2) { return point(p1.x - p2.x, p1.y - p2.y); }   struct line {     point p, v;     line() {}     line(point p, point v) : p(p), v(v) {}   };   bool belongs(point p, line l) { return prodvec(l.p - p, l.v) == 0; }   int n;   vector<vector<double> > operator*(vector<vector<double> > m1,                                     vector<vector<double> > m2) {     vector<vector<double> > m(n, vector<double>(n, 0));     for (int i = 0; i < n; i++)       for (int j = 0; j < n; j++)         for (int k = 0; k < n; k++) m[i][j] += m1[i][k] * m2[k][j];     return m;   }   vector<double> operator*(vector<double> v, vector<vector<double> > m) {     vector<double> r(n, 0);     for (int j = 0; j < n; j++)       for (int i = 0; i < n; i++) r[j] += v[i] * m[i][j];     return r;   }   const int limit = 205;   point p[limit];   int nl;   vector<int> p2l[limit];   vector<int> l2p[limit * limit];   const int tope = 15;   vector<vector<double> > vm[tope];   int main() {     cout.setf(ios::fixed);     cout.precision(10);     ios::sync_with_stdio(false);     cin >> n;     for (int i = 0; i < n; i++) cin >> p[i].x >> p[i].y;     for (int i = 0; i < n; i++) {       for (int j = i + 1; j < n; j++) {         line l(p[i], p[j] - p[i]);         bool error = false;         for (int k = 0; k < j and not error; k++)           error = k != i and belongs(p[k], l);         if (not error) {           for (int k = 0; k < n; k++) {             if (belongs(p[k], l)) {               p2l[k].push_back(nl);               l2p[nl].push_back(k);             }           }           nl++;         }       }     }     vector<vector<double> > m(n, vector<double>(n, 0));     for (int u = 0; u < n; u++) {       vector<int> &vl = p2l[u];       int nvl = int(vl.size());       for (int ivl = 0; ivl < nvl; ivl++) {         int l = vl[ivl];         vector<int> &vu = l2p[l];         int nvu = int(vu.size());         for (int ivu = 0; ivu < nvu; ivu++) {           int v = vu[ivu];           m[v][u] += 1.0 / nvl / nvu;         }       }     }     vm[0] = m;     for (int steps = 1; steps < tope; steps++)       vm[steps] = vm[steps - 1] * vm[steps - 1];     int cases;     cin >> cases;     for (int cas = 0; cas < cases; cas++) {       int p, t;       cin >> p >> t;       p--;       t--;       vector<double> V(n, 0);       V[p] = 1;       for (int b = 0; b < tope; b++)         if (t & (1 << b)) V = V * vm[b];       double sol = 0;       vector<int> vl = p2l[p];       int nvl = int(vl.size());       for (int ivl = 0; ivl < nvl; ivl++) {         int l = vl[ivl];         double pl = 0;         vector<int> &vu = l2p[l];         int nvu = int(vu.size());         for (int ivu = 0; ivu < nvu; ivu++) {           int v = vu[ivu];           pl += 1.0 / nvu * V[v];         }         maximize(sol, pl);       }       cout << sol << endl;     }   }   