add HELPBTW

helpbtw.cpp

@@ -0,0 +1,46 @@
+// 2016-10-26
+#include <climits>
+#include <cstdio>
+#include <algorithm>
+#include <vector>
+using namespace std;
+bool ok(const vector<int>& a, int range, int days, int target) {
+    vector<long long> ex(a.size());
+    long long cur = 0;
+    long long used = 0;
+    for (int i = 0; i < a.size(); i++) {
+        cur -= ex[i];
+        long long increment = target - a[i] - cur;
+        if (increment > 0) {
+            used += increment;
+            cur += increment;
+            if (i + range < a.size()) {
+                ex[i + range] += increment;
+            }
+        }
+    }
+    return used <= days;
+}
+int main() {
+    int T; scanf("%d", &T);
+    while (T--) {
+        int N, M, K; scanf("%d %d %d", &N, &M, &K);
+        vector<int> a(N);
+        for (int& x : a) scanf("%d", &x);
+        if (M == 0) {
+            // evil special case
+            printf("%d\n", *min_element(a.begin(), a.end()));
+        } else {
+            int l = 0, r = 2000000000;
+            while (r > l) {
+                int m = l + (r - l + 1)/2;
+                if (ok(a, M, K, m)) {
+                    l = m;
+                } else {
+                    r = m - 1;
+                }
+            }
+            printf("%d\n", l);
+        }
+    }
+}