new file: P3205.cpp

P3205.cpp

@@ -0,0 +1,24 @@
+#include<bits/stdc++.h>
+using namespace std;
+const int mod = 19650827;
+int n;
+int a[1005];
+int f[1005][1005];
+int g[1005][1005];
+int main() {
+    scanf("%d", &n);
+    for(int i = 1; i <= n; ++i) {
+        scanf("%d", &a[i]);
+        f[i][i] = 1;
+        // g[i][i] = 1;
+    }
+    for(int len = 1; len < n; ++len) {
+        for(int l = 1; l + len <= n; ++l) {
+            int r = l + len;
+            f[l][r] = (f[l + 1][r] * (a[l] < a[l + 1]) + g[l + 1][r] * (a[l] < a[r])) % mod;
+            g[l][r] = (f[l][r - 1] * (a[l] < a[r]) + g[l][r - 1] * (a[r - 1] < a[r])) % mod;
+        }
+    }
+    printf("%d\n", (f[1][n] + g[1][n]) % mod);
+    return 0;
+}