D - Snuke Panic (1D)

https://atcoder.jp/contests/abc266/submissions/34405932

AtCoder/ABC266/D/D.cpp

@@ -0,0 +1,60 @@
+#include <iostream>
+#include <algorithm>
+#include <array>
+#include <limits>
+#include <utility>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5;
+
+int n, min_t, max_t;
+std::array<long long, 5> f[N];
+std::array<std::pair<int, int>, N> snukes;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    min_t = std::numeric_limits<int>::max();
+    max_t = std::numeric_limits<int>::min();
+    std::fill(snukes.begin(), snukes.end(), std::make_pair(-1, 0));
+
+    for (int i = 1, t, x, a; i <= n; i++) {
+        cin >> t >> x >> a;
+
+        snukes[t] = std::make_pair(x, a);
+        min_t = std::min(min_t, t);
+        max_t = std::max(max_t, t);
+    }
+
+    f[0][1] = f[0][2] = f[0][3] = f[0][4]
+        = f[1][1] = f[1][2] = f[1][3] = f[1][4]
+        = f[2][2] = f[2][3] = f[2][4]
+        = f[3][3] = f[3][4]
+        = std::numeric_limits<long long>::min();
+
+    for (int i = 1; i <= max_t; i++) {
+        std::copy_n(f[i - 1].begin(), std::min(i, 5), f[i].begin());
+
+        if (snukes[i].first == -1) continue;
+
+        long long x = std::numeric_limits<long long>::min();
+
+        for (int j = 0; j <= 4; j++) {
+            if (i - std::abs(j - snukes[i].first) < 0) continue;
+
+            x = std::max(x, f[i - std::abs(j - snukes[i].first)][j] + snukes[i].second);
+        }
+
+        f[i][snukes[i].first] = std::max(f[i][snukes[i].first], x);
+    }
+
+    cout << std::max({f[max_t][0], f[max_t][1], f[max_t][2], f[max_t][3], f[max_t][4]}) << endl;
+
+    return 0;
+}