#include <bits/stdc++.h> #include "obstacles.h" using namespace std; static int N, M; static vector<int> Tval, Hval; static vector<int> c; // blocked/free static vector<int> sum; // prefix sum of blocked cells static vector<int> left; // nearest blocked to the left static vector<int> right; // nearest blocked to the right static int d; // temperature of first row // Segment tree for range minimum query static vector<int> seg; // Build segment tree void build(int node, int l, int r) { if (l == r) { seg[node] = Hval[l]; return; } int mid = (l + r) / 2; build(2*node, l, mid); build(2*node+1, mid+1, r); seg[node] = min(seg[2*node], seg[2*node+1]); } // Query min in range [ql..qr] int query(int node, int l, int r, int ql, int qr) { if (r < ql || l > qr) return INT_MAX; if (ql <= l && r <= qr) return seg[node]; int mid = (l + r) / 2; return min(query(2*node, l, mid, ql, qr), query(2*node+1, mid+1, r, ql, qr)); } void initialize(vector<int> T, vector<int> H) { Tval = T; Hval = H; N = Tval.size(); M = Hval.size(); d = Tval[0]; // first row temperature c.assign(M, 0); sum.assign(M, 0); left.assign(M, -1); right.assign(M, M); for (int i = 0; i < M; i++) c[i] = (Hval[i] >= d); // blocked if Hval >= d // prefix sum of blocked cells sum[0] = c[0]; for (int i = 1; i < M; i++) sum[i] = sum[i-1] + c[i]; // nearest blocked to the right int last = M; for (int i = M-1; i >= 0; i--) { if (c[i]) last = i; else right[i] = last - 1; } // nearest blocked to the left last = -1; for (int i = 0; i < M; i++) { if (c[i]) last = i; else left[i] = last + 1; } // build segment tree for Hval seg.assign(4*M, INT_MAX); build(1, 0, M-1); } bool can_reach(int L, int R, int S, int D) { if (S > D) swap(S, D); int min_in_range = query(1, 0, M-1, S, D); // If temperature > max humidity in the path, llama can go if (d > min_in_range) return true; // Also check if prefix sums indicate fully free path int blocked = sum[D] - (S > 0 ? sum[S-1] : 0); if (blocked == 0) return true; return false; }

obstacles.cpp: In function 'void initialize(std::vector<int>, std::vector<int>)':
obstacles.cpp:47:5: error: reference to 'left' is ambiguous
   47 |     left.assign(M, -1);
      |     ^~~~
In file included from /usr/include/c++/13/streambuf:43,
                 from /usr/include/c++/13/bits/streambuf_iterator.h:35,
                 from /usr/include/c++/13/iterator:66,
                 from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:54,
                 from obstacles.cpp:1:
/usr/include/c++/13/bits/ios_base.h:1042:3: note: candidates are: 'std::ios_base& std::left(ios_base&)'
 1042 |   left(ios_base& __base)
      |   ^~~~
obstacles.cpp:9:20: note:                 'std::vector<int> left'
    9 | static vector<int> left;     // nearest blocked to the left
      |                    ^~~~
obstacles.cpp:48:5: error: reference to 'right' is ambiguous
   48 |     right.assign(M, M);
      |     ^~~~~
/usr/include/c++/13/bits/ios_base.h:1050:3: note: candidates are: 'std::ios_base& std::right(ios_base&)'
 1050 |   right(ios_base& __base)
      |   ^~~~~
obstacles.cpp:10:20: note:                 'std::vector<int> right'
   10 | static vector<int> right;    // nearest blocked to the right
      |                    ^~~~~
obstacles.cpp:62:14: error: reference to 'right' is ambiguous
   62 |         else right[i] = last - 1;
      |              ^~~~~
/usr/include/c++/13/bits/ios_base.h:1050:3: note: candidates are: 'std::ios_base& std::right(ios_base&)'
 1050 |   right(ios_base& __base)
      |   ^~~~~
obstacles.cpp:10:20: note:                 'std::vector<int> right'
   10 | static vector<int> right;    // nearest blocked to the right
      |                    ^~~~~
obstacles.cpp:69:14: error: reference to 'left' is ambiguous
   69 |         else left[i] = last + 1;
      |              ^~~~
/usr/include/c++/13/bits/ios_base.h:1042:3: note: candidates are: 'std::ios_base& std::left(ios_base&)'
 1042 |   left(ios_base& __base)
      |   ^~~~
obstacles.cpp:9:20: note:                 'std::vector<int> left'
    9 | static vector<int> left;     // nearest blocked to the left
      |                    ^~~~