another 4 sorting and searching problems

CSES - CSES Problem Set/Maximum_Subarray_Sum.cpp

@@ -0,0 +1,19 @@
+//  Maximum Subarray Sum
+
+#include<bits/stdc++.h>
+
+using namespace std;
+using ll = long long;
+
+int main() {
+    int n; cin >> n;
+    ll max_sum = INT32_MIN;
+    ll current_sum = INT32_MIN;
+    for (int i{}; i < n; i++) {
+        ll a; cin >> a;
+        current_sum = max(current_sum + a, a);
+        max_sum = max(current_sum, max_sum);
+    }
+    cout << max_sum << endl;
+    return 0;
+}

CSES - CSES Problem Set/Movie_Festival.cpp

@@ -0,0 +1,28 @@
+//  Movie Festival
+
+#include<bits/stdc++.h>
+
+using namespace std;
+using ll = long long;
+
+int main() {
+    int n; cin >> n;
+    vector<pair<ll, ll>> movies(n);
+    for (auto &p: movies) {
+        ll a, b; cin >> a >> b;
+        p = {b, a};
+    }
+    int count = 0;
+    int current_time = 0;
+    std::sort(movies.begin(), movies.end());
+    for (auto &[end, start]: movies) {
+        if (start >= current_time) {
+            current_time = end;
+            count++;
+        }
+    }
+
+    cout << count << endl;
+
+    return 0;
+}

CSES - CSES Problem Set/Restaurant_Customers.cpp

@@ -0,0 +1,25 @@
+//  Restaurant Customers
+
+#include<bits/stdc++.h>
+
+using namespace std;
+using ll = long long;
+
+int main() {
+    int n; cin >> n;
+    map<ll, int> m;
+    for (int i{}; i < n; i++) {
+        ll a, b;
+        cin >> a >> b;
+        m[a]++;
+        m[b]--;
+    }
+    int max_count = 0;
+    int count = 0;
+    for (auto &[t, c]: m) {
+        count += c;
+        max_count = max(max_count, count);
+    }
+    cout << max_count << endl;
+    return 0;
+}

CSES - CSES Problem Set/Sum_of_Two_Values.cpp

@@ -0,0 +1,33 @@
+//  Sum of Two Values
+
+#include<bits/stdc++.h>
+
+using namespace std;
+using ll = long long;
+
+int main() {
+    map<ll, vector<int>> input;
+    int n; cin >> n;
+    ll x; cin >> x;
+    vector<ll> in;
+    for (int i{}; i < n; i++) {
+        ll a; cin >> a;
+        input[a].push_back(i);
+        in.push_back(a);
+    }
+    for (int i{}; i < n; i++) {
+        ll target = x - in[i];
+        bool flag = target == in[i];
+        if (input[target].empty() || (input[target].size() == 1 && flag)) continue;
+        else {
+            if (flag) {
+                cout << i + 1 << " " << input[target][1] + 1<< endl;
+            } else {
+                cout << i + 1 <<  " " << input[target][0] + 1<< endl;
+            }
+            return 0;
+        }
+    }
+    cout << "IMPOSSIBLE" << endl;
+    return 0;
+}