Create day07sol02.cpp

Author: suzzzal

Problems/Binary-Search/Day-07/sol/suzzzal/day07sol02.cpp

@@ -0,0 +1,92 @@
+//subission link - https://codeforces.com/contest/1777/submission/356090266
+
+
+/*
+ * APPROACH:
+ * Line up all students from least to most smart. Add them to the team one by one until 
+ * they know all the topics. Once they do, try removing the least smart student to make 
+ * the smartness gap as small as possible while still covering every topic.
+ */
+
+#include <bits/stdc++.h>
+
+using namespace std;
+
+const int MAX_VAL = 100005;
+
+vector<int> divs[MAX_VAL];
+
+void precompute() {
+    for (int i = 1; i < MAX_VAL; i++) {
+        for (int j = i; j < MAX_VAL; j += i) {
+            divs[j].push_back(i);
+        }
+    }
+}
+
+void solve() {
+    int n, m;
+    cin >> n >> m;
+
+    vector<int> a(n);
+    for (int i = 0; i < n; i++) {
+        cin >> a[i];
+    }
+
+    sort(a.begin(), a.end());
+
+    vector<int> freq(m + 1, 0);
+    
+    int covered_cnt = 0;
+    int min_diff = INT_MAX;
+    int left = 0;
+
+    for (int right = 0; right < n; right++) {
+        int current_smartness = a[right];
+
+        for (int d : divs[current_smartness]) {
+            if (d > m) continue;
+
+            if (freq[d] == 0) {
+                covered_cnt++;
+            }
+            freq[d]++;
+        }
+
+        while (covered_cnt == m) {
+            min_diff = min(min_diff, a[right] - a[left]);
+
+            int remove_smartness = a[left];
+            for (int d : divs[remove_smartness]) {
+                if (d > m) continue;
+
+                freq[d]--;
+                if (freq[d] == 0) {
+                    covered_cnt--;
+                }
+            }
+            left++;
+        }
+    }
+
+    if (min_diff == INT_MAX) {
+        cout << -1 << endl;
+    } else {
+        cout << min_diff << endl;
+    }
+}
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    precompute();
+
+    int t;
+    cin >> t;
+    while (t--) {
+        solve();
+    }
+
+    return 0;
+}