From af869f388761ad8903757f0921000f0e7968ef0f Mon Sep 17 00:00:00 2001
From: Ren Baoshuo <i@baoshuo.ren>
Date: Wed, 30 Jun 2021 10:52:21 +0800
Subject: [PATCH] =?UTF-8?q?#421.=20=E5=87=A0=E4=BD=95=E9=97=AE=E9=A2=98?=
 =?UTF-8?q?=E4=B8=80?=
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https://sjzezoj.com/submission/12026
---
 S2OJ/421/421.cpp | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 S2OJ/421/421.cpp

diff --git a/S2OJ/421/421.cpp b/S2OJ/421/421.cpp
new file mode 100644
index 00000000..a6f407b4
--- /dev/null
+++ b/S2OJ/421/421.cpp
@@ -0,0 +1,46 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+long long n, m, k, a[100005], sum[100005], ans;
+
+long long getSum(long long l, long long r) {
+    long long len = r - l + 1;
+    if (len % 2 == 0) {
+        long long mid = l + (len / 2) - 1;
+        return sum[r] - sum[mid] - (sum[mid] - sum[l - 1]);
+    } else {
+        long long mid = l + r >> 1;
+        return sum[r] - sum[mid] - (sum[mid - 1] - sum[l - 1]);
+    }
+    return -1;
+}
+
+bool check(long long x) {
+    for (long long i = 1; i + x - 1 <= n; i++) {
+        if (getSum(i, i + x - 1) <= k) {
+            return true;
+        }
+    }
+    return false;
+}
+
+int main() {
+    cin >> n >> m >> k;
+    for (long long i = 1; i <= n; i++) {
+        cin >> a[i];
+        sum[i] = sum[i - 1] + a[i];
+    }
+    long long l = 1, r = n;
+    while (l <= r) {
+        long long mid = l + r >> 1;
+        if (check(mid)) {
+            ans = mid;
+            l = mid + 1;
+        } else {
+            r = mid - 1;
+        }
+    }
+    cout << ans << endl;
+    return 0;
+}