array division

CSES - CSES Problem Set/Sorting_And_Searching/Array_Division.cpp

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+//  Array Division
+
+#include<bits/stdc++.h>
+
+using namespace std;
+using ll = long long;
+
+bool check_sum(vector<ll> &a, ll target_sum, int max_number_of_sub_arrays) {
+    ll sum = 0;
+    ll count = 1;
+    for (int i{}; i < a.size(); i++) {
+        if (sum + a[i] <= target_sum) {
+            sum += a[i];
+        } else {
+            sum = a[i];
+            if (sum > target_sum) return false;
+            count++;
+        }
+    }
+    return count <= max_number_of_sub_arrays;
+}
+
+int main() {
+    int n, k; cin >> n >> k;
+    vector<ll> a(n);
+    ll sum = 0;
+    for (int i{}; i < n; i++) {
+        cin >> a[i];
+        sum += a[i];
+    }
+    ll lo = 0;
+    ll hi = INT64_MAX / 3;
+    while (lo < hi) {
+        ll mid = (lo + hi) / 2;
+        if (check_sum(a, mid, k)) {
+            hi = mid;
+        } else {
+            lo = mid + 1;
+        }
+    }
+    cout << lo << endl;
+}