From 24213fc267c4bab1f6c51f1ab7a64070791e0eab Mon Sep 17 00:00:00 2001
From: Baoshuo <i@baoshuo.ren>
Date: Wed, 17 Jul 2024 10:39:11 +0800
Subject: [PATCH] P2947 [USACO09MAR] Look Up S

https://www.luogu.com.cn/record/166555989
---
 Luogu/P2947/P2947.cpp | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 Luogu/P2947/P2947.cpp

diff --git a/Luogu/P2947/P2947.cpp b/Luogu/P2947/P2947.cpp
new file mode 100644
index 00000000..d072ccc0
--- /dev/null
+++ b/Luogu/P2947/P2947.cpp
@@ -0,0 +1,37 @@
+#include <iostream>
+#include <stack>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5;
+
+int n, h[N], ans[N];
+std::stack<int> st;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> h[i];
+    }
+
+    for (int i = n; i; i--) {
+        // pop all elements that are smaller than h[i]
+        while (!st.empty() && h[i] >= h[st.top()]) st.pop();
+        // if the stack is not empty, the nearest element that is larger than h[i] is st.top()
+        if (!st.empty()) ans[i] = st.top();
+        // push h[i] into the stack
+        st.push(i);
+    }
+
+    for (int i = 1; i <= n; i++) {
+        cout << ans[i] << endl;
+    }
+
+    return 0;
+}