#include <bits/stdc++.h> #define int long long using namespace std; using pii = pair<int, int>; void solve() { int n, kk; cin >> n >> kk; vector<pii> v(n); for (auto &[b, a] : v) { cin >> a >> b; if (b == -1) b = INT_MAX; } sort(v.begin(), v.end()); for (auto &[b, a] : v) if (b == INT_MAX) b = -1; vector<int> a(n), b(n); for (int i = 0; i < n; ++i) a[i] = v[i].second, b[i] = v[i].first; cout << fixed << setprecision(10); vector<vector<vector<double>>> dp(n + 1, vector<vector<double>>(n + 1, vector<double>(n + 2, 1e15))); dp[0][0][1] = 0; for (int i = 0; i < n; ++i) { dp[i + 1] = dp[i]; for (int j = 0; j < n; ++j) for (int k = 1; k < n + 2; ++k) { dp[i + 1][j + 1][k] = min(dp[i + 1][j + 1][k], dp[i][j][k] + 1.0 * a[i] / k); if (b[i] != -1 && k != n + 1) dp[i + 1][j + 1][k + 1] = min(dp[i + 1][j + 1][k + 1], dp[i][j][k] + 1.0 * b[i] / k); } } double ans = 1e15; for (int i = 0; i <= n; ++i) for (int j = kk; j <= kk; ++j) for (int k = 0; k < n + 2; ++k) ans = min(ans, dp[i][j][k]); assert(ans < 1e14); cout << ans << '\n'; // for (auto i : dp[n]) // { // for (auto j : i) // cout << j << ' '; // cout << '\n'; // } } signed main() { ios::sync_with_stdio(0); cin.tie(0); solve(); return 0; }

Main.cpp: In function 'void solve()':
Main.cpp:11:16: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   11 |     for (auto &[b, a] : v)
      |                ^
Main.cpp:18:16: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   18 |     for (auto &[b, a] : v)
      |                ^