#include "aliens.h" #include <algorithm> #include <queue> #define x first #define y second long long sq(int a) { return a * a; } bool cmp(std::pair<int, int> a, std::pair<int, int> b) { if (a.x == b.x) return (a.y > b.y); return a.x < b.y; } long long dp[100001], cnt[100001]{1}; float slope(int i, int j, std::vector<std::pair<int, int>> points) { return (float)(sq(points[j + 1].y) - sq(points[i + 1].y) + dp[j] - dp[i] + sq(std::max(points[i].x - points[i + 1].y + 1, 0)) - sq(std::max(points[j].x - points[j + 1].y + 1, 0))) / (points[j + 1].y - points[i + 1].y); } void compute(int lambda, std::vector<std::pair<int, int>> points, int k) { std::deque<int> dq; dq.push_back(0); dp[0] = lambda + sq(points[0].y - points[0].x + 1); for (int i = 1; i < points.size(); i++) { while (dq.size() > 1 && slope(dq[0], dq[1], points) >= 2 * (points[i].x + 1)) dq.pop_front(); int opt = dq.front(); dp[i] = sq(points[i].y - points[opt + 1].x + 1) + dp[opt] - sq(std::max(0, points[opt].x - points[opt + 1].y + 1)) + lambda; cnt[i] = cnt[opt] + 1; while (dq.size() > 1 && slope(dq[dq.size() - 2], dq.back(), points) <= slope(dq.back(), i, points)) dq.pop_back(); dq.push_back(i); } } long long take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c) { std::vector<std::pair<int, int>> points, useful; for (int i = 0; i < n; i++) { int x = r[i], y = c[i]; if (x > y) std::swap(x, y); points.push_back({x, y}); } std::sort(points.begin(), points.end(), cmp); for (int i = 0; i < n; i++) if (useful.empty() || useful.back().y < points[i].y) useful.push_back(points[i]); long long l = 0, u = 1e9; while (l != u) { long long mid = (l + u + 1) / 2; compute(mid, useful, k); if (cnt[useful.size() - 1] <= k) l = mid; else u = mid; } compute(l, useful, k); return dp[useful.size() - 1] - l * cnt[useful.size() - 1]; }

aliens.cpp: In function 'void compute(int, std::vector<std::pair<int, int> >, int)':
aliens.cpp:27:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 1; i < points.size(); i++) {
                     ~~^~~~~~~~~~~~~~~