E - Tahakashi and Animals

https://atcoder.jp/contests/abc251/submissions/31683208

AtCoder/ABC251/E/E.cpp

@@ -0,0 +1,41 @@
+#include <algorithm>
+#include <cstring>
+#include <iostream>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 3e5 + 5;
+
+int n;
+long long a[N], f[N][2], g[N][2];
+
+int main() {
+    std::ios::sync_with_stdio(false);
+
+    cin >> n;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+    }
+
+    memset(f, 0x3f, sizeof(f));
+    memset(g, 0x3f, sizeof(g));
+
+    f[1][1] = a[1];
+    for (int i = 2; i <= n; i++) {
+        f[i][0] = f[i - 1][1];
+        f[i][1] = std::min({f[i][1], f[i - 1][0] + a[i], f[i - 1][1] + a[i]});
+    }
+
+    g[1][0] = a[n];
+    for (int i = 2; i < n; i++) {
+        g[i][0] = g[i - 1][1];
+        g[i][1] = std::min({g[i][1], g[i - 1][0] + a[i], g[i - 1][1] + a[i]});
+    }
+
+    cout << std::min({f[n][0], f[n][1], g[n - 1][0], g[n - 1][1]}) << endl;
+
+    return 0;
+}