new file: P4342.cpp

P4342.cpp

@@ -0,0 +1,61 @@
+#include <bits/stdc++.h>
+using namespace std;
+int n;
+char op[105];
+long long a[105];
+long long f[105][105];
+long long g[105][105];
+void getc(char &c) {
+    c = getchar_unlocked();
+    while(c != 't' && c != 'x') c = getchar_unlocked();
+}
+int main() {
+    scanf("%d", &n);
+    for (int i = 1; i <= n; ++i) {
+        getc(op[i]);
+        scanf("%lld", &a[i]);
+        a[i + n] = a[i];
+        op[i + n] = op[i];
+    }
+    for (int i = 1; i <= 2 * n; ++i) {
+        f[i][i] = a[i];
+        g[i][i] = a[i];
+    }
+    for (int len = 2; len <= n; ++len) {
+        for (int l = 1; l + len - 1 <= 2 * n; ++l) {
+            int r = l + len - 1;
+            f[l][r] = LLONG_MIN;
+            g[l][r] = LLONG_MAX;
+            for (int k = l; k < r; ++k) {
+                char o = op[k + 1];
+                if (o == 't') {
+                    f[l][r] = max(f[l][r], f[l][k] + f[k + 1][r]);
+                    g[l][r] = min(g[l][r], g[l][k] + g[k + 1][r]);
+                } else {
+                    long long v1 = f[l][k] * f[k + 1][r];
+                    long long v2 = f[l][k] * g[k + 1][r];
+                    long long v3 = g[l][k] * f[k + 1][r];
+                    long long v4 = g[l][k] * g[k + 1][r];
+                    f[l][r] = max({f[l][r], v1, v2, v3, v4});
+                    g[l][r] = min({g[l][r], v1, v2, v3, v4});
+                }
+            }
+        }
+    }
+    long long ans = LLONG_MIN;
+    vector<int> anss;
+    for (int l = 1; l <= n; ++l) {
+        int r = l + n - 1;
+        // printf("%lld\n", f[l][r]);
+        if (f[l][r] > ans) {
+            ans = f[l][r];
+            anss.clear();
+            anss.push_back(l);
+        } else if(f[l][r] == ans) {
+            anss.push_back(l);
+        }
+    }
+    printf("%lld\n", ans);
+    for(int i:anss) printf("%d ", i);
+    return 0;
+}