P5788 【模板】单调栈

R54824971

Luogu/problem/P5788/P5788.cpp

@@ -0,0 +1,24 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int n, a[3000005], f[3000005];
+stack<int> st;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin >> n;
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+    }
+    for (int i = n; i >= 1; i--) {
+        while (!st.empty() && a[st.top()] <= a[i]) st.pop();
+        f[i] = st.empty() ? 0 : st.top();
+        st.push(i);
+    }
+    for (int i = 1; i <= n; i++) {
+        cout << f[i] << ' ';
+    }
+    cout << endl;
+    return 0;
+}