new file: P11309.cpp

P11309.cpp

@@ -0,0 +1,33 @@
+#include <bits/stdc++.h>
+#define int long long
+using namespace std;
+int t;
+int n, k;
+int a[100005];
+long long calc() {
+    long long ans = 0;
+    int nowmax = 0;
+    for (int i = 1; i <= n; ++i) {
+        nowmax = max(a[i], nowmax), ans += nowmax;
+    }
+    return ans;
+}
+signed main() {
+    scanf("%lld", &t);
+    while (t--) {
+        scanf("%lld%lld", &n, &k);
+        int ma = 0;
+        for (int i = 1; i <= n; ++i) {
+            scanf("%lld", &a[i]), ma = max(ma, a[i]);
+        }
+        if (k == 0)
+            printf("%lld\n", calc());
+        else if (n == 2) {
+            if (k % 2 == 1)
+                swap(a[1], a[2]);
+            printf("%lld\n", a[1] + max(a[1], a[2]));
+        } else
+            printf("%lld\n", 1ll * n * ma);
+    }
+    return 0;
+}