pastbook2 dp_u

cargo-compete/pastbook2/Cargo.toml

@@ -29,6 +29,7 @@ edition = "2018"
 143 = { alias = "pastbook2022_c", problem = "https://atcoder.jp/contests/pastbook2022/tasks/pastbook2022_c" }
 146 = { alias = "dp_p", problem = "https://atcoder.jp/contests/dp/tasks/dp_p" }
 149 = { alias = "dp_s", problem = "https://atcoder.jp/contests/dp/tasks/dp_s" }
+154 = { alias = "dp_u", problem = "https://atcoder.jp/contests/dp/tasks/dp_u" }
 
 [[bin]]
 name = "027"
@@ -126,6 +127,10 @@ path = "src/bin/146.rs"
 name = "149"
 path = "src/bin/149.rs"
 
+[[bin]]
+name = "154"
+path = "src/bin/154.rs"
+
 [dependencies]
 num = "=0.2.1"
 num-bigint = "=0.2.6"

cargo-compete/pastbook2/README.md

@@ -25,3 +25,4 @@
 - P.143 各部分木の大きさ (オリジナル問題) <https://atcoder.jp/contests/pastbook2022/tasks/pastbook2022_c>
 - P.146 Independent Set (Educational DP Contest:P問題) <https://atcoder.jp/contests/dp/tasks/dp_p>
 - P.149 Digit Sum (Educational DP Contest:S問題) <https://atcoder.jp/contests/dp/tasks/dp_s>
+- P.154 Grouping (Educational DP Contest:U問題) <https://atcoder.jp/contests/dp/tasks/dp_u>

cargo-compete/pastbook2/src/bin/154.rs

@@ -0,0 +1,35 @@
+use proconio::input;
+
+fn main() {
+    input! {
+        n: usize,
+        a: [[i64; n]; n],
+    }
+
+    let mut score = vec![0_i64; 1 << n];
+    for (s, score_s) in score.iter_mut().enumerate() {
+        for (i, a_i) in a.iter().enumerate() {
+            for j in i + 1..n {
+                if ((s & (1 << i)) != 0) && ((s & (1 << j)) != 0) {
+                    *score_s += a_i[j];
+                }
+            }
+        }
+    }
+
+    let mut dp = vec![0_i64; 1 << n];
+    for s in 0_usize..(1 << n) {
+        // 集合 s の部分集合 t を走査
+        let mut prev = None;
+        let mut t = s;
+        while prev != Some(t) {
+            t &= s;
+            dp[s] = dp[s].max(dp[t] + score[s ^ t]);
+            prev = Some(t);
+            t = t.saturating_sub(1);
+        }
+    }
+
+    let ans = dp[(1 << n) - 1];
+    println!("{}", ans);
+}