new: France-IOI Algorithmes Gloutons

Author: omar-besbes

solutions/France-IOI/Niveau 5/Algorithmes Gloutons/Caméras de surveillance.cpp

@@ -0,0 +1,53 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+template <class U>
+void merge(set<U> &a, set<U> &b) {
+   for(auto &i: b) a.insert(i);
+   b.clear();
+}
+
+typedef tuple<int, int, int> edge;
+
+int main() {
+   ios::sync_with_stdio(false);
+   cin.tie(0);
+   cout.tie(0);
+
+   int n, a;
+   cin >> n >> a;
+   vector<set<tuple<int, int, int>>> adj(n, set<tuple<int, int, int>>());
+   for (int i = 0; i < a; i++) {
+      int a, b, w;
+      cin >> a >> b >> w;
+      a--, b--;
+      adj[a].insert(make_tuple(w, a, b));
+      adj[b].insert(make_tuple(w, b, a));
+   }
+
+   vector<bool> selected(n, false);
+   set<edge> mst;
+
+   int ans = 0, nb = 1;
+   selected[0] = true;
+   set<edge> q;
+   merge(q, adj[0]);
+
+   while (nb < n) {
+      int w, a, b;
+      auto e = *q.begin();
+      tie(w, a, b) = e;
+      q.erase(make_tuple(w, b, a));
+      q.erase(make_tuple(w, a, b));
+
+      if (selected[a] && selected[b]) continue;
+      if (!selected[a]) selected[a] = true, merge<edge>(q, adj[a]);
+      if (!selected[b]) selected[b] = true, merge<edge>(q, adj[b]);
+
+      mst.insert(e);
+      ans += w;
+      nb++;
+   }
+
+   cout << ans << "\n";
+}

solutions/France-IOI/Niveau 5/Algorithmes Gloutons/Chaîne de production.cpp

@@ -0,0 +1,46 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define pii pair<int, int>
+#define all(x) x.begin(), x.end()
+
+vector<int> solve(vector<int>& machines, vector<int>& jobs) {
+   sort(all(jobs));
+   int m = machines.size(), j = jobs.size();
+   vector<int> cum(m, 0), ans(j, INT_MAX);
+   for (int job = 0; job < j; job++) {
+      pii mini = make_pair(INT_MAX, -1);
+      for (int i = 0; i < m; i++)
+         mini = min(mini, make_pair(cum[i] + machines[i], i));
+      ans[job] = mini.first;
+      cum[mini.second] = mini.first;
+   }
+   sort(all(ans));
+   for (int job = 0; job < j; job++) ans[job] += jobs[j - job - 1];
+   return ans;
+}
+
+int main() {
+   ios::sync_with_stdio(false);
+   cin.tie(0);
+   cout.tie(0);
+
+   int n;
+   cin >> n;
+   int A;
+   cin >> A;
+   vector<int> a(A);
+   for (auto& i : a) cin >> i;
+   int B;
+   cin >> B;
+   vector<int> b(B);
+   for (auto& i : b) cin >> i;
+
+   vector<int> input(n, 0);
+   auto output1 = solve(a, input);
+   auto ans1 = *max_element(all(output1));
+   cout << ans1 << "\n";
+
+   auto output2 = solve(b, output1);
+   auto ans2 = *max_element(all(output2));
+   cout << ans2 << "\n";
+}

solutions/France-IOI/Niveau 5/Algorithmes Gloutons/Fête du cinéma.cpp

@@ -0,0 +1,22 @@
+#include "bits/stdc++.h"
+using namespace std;
+
+int main() {
+   ios_base::sync_with_stdio(false);
+   cin.tie(nullptr);
+
+   int n;
+   cin >> n;
+   vector<pair<int, int>> s(n);
+   for (auto &item : s) cin >> item.first >> item.second;
+
+   sort(s.begin(), s.end(),
+        [](pair<int, int> x, pair<int, int> y) { return x.second < y.second; });
+
+   auto ans = 0, cur = 0;
+   for (int i = 0; i < n; i++) {
+      if (s[i].first >= cur) cur = s[i].second + 1, ans++;
+   }
+
+   cout << ans << "\n";
+}