1283. 登山

http://ybt.ssoier.cn:8088/statusx.php?runidx=15574048

ybt/1283/1283.cpp

@@ -0,0 +1,39 @@
+#include <iostream>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1005;
+
+int n, a[N], f1[N], f2[N], ans;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+
+    cin >> n;
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+    }
+
+    for (int i = 1; i <= n; i++) {
+        f1[i] = 1;
+        for (int j = 1; j < i; j++) {
+            if (a[i] > a[j]) f1[i] = std::max(f1[i], f1[j] + 1);
+        }
+    }
+    for (int i = n; i; i--) {
+        f2[i] = 1;
+        for (int j = n; j > i; j--) {
+            if (a[i] > a[j]) f2[i] = std::max(f2[i], f2[j] + 1);
+        }
+    }
+
+    for (int i = 1; i <= n; i++) {
+        ans = std::max(ans, f1[i] + f2[i] - 1);
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}