P1956 Sum

https://www.luogu.com.cn/record/96691668

Luogu/P1956/P1956.cpp

@@ -0,0 +1,43 @@
+#include <iostream>
+#include <limits>
+#include <set>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5;
+
+int n;
+long long k, p, s[N],
+    ans = std::numeric_limits<long long>::max();
+std::set<long long> set{{0}};
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> k >> p;
+
+    for (int i = 1; i <= n; i++) {
+        long long x;
+
+        cin >> x;
+
+        s[i] = (s[i - 1] + x) % p;
+    }
+
+    for (int i = 1; i <= n; i++) {
+        if (s[i] < k) {
+            ans = std::min(ans, s[i] + p - *--set.upper_bound(s[i] - k + p));
+        } else {
+            ans = std::min(ans, s[i] - *--set.upper_bound(s[i] - k));
+        }
+
+        set.emplace(s[i]);
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}