tessoku-book a57

tessoku-book/src/bin/a57.rs

@@ -3,8 +3,31 @@ use proconio::{input, marker::Usize1};
 fn main() {
     input! {
         n: usize,
+        q: usize,
         a: [Usize1; n],
+        xy: [(Usize1, usize); q],
     };
-    let ans = n - a.len();
-    println!("{}", ans);
+
+    let m = 30;
+    let mut dp = vec![vec![0_usize; n]; m + 1];
+    for (i, a_i) in a.iter().copied().enumerate() {
+        dp[0][i] = a_i;
+    }
+    for i in 1..=m {
+        for j in 0..n {
+            dp[i][j] = dp[i - 1][dp[i - 1][j]];
+        }
+    }
+
+    for (x, y) in xy {
+        let mut cur = x;
+        let mut cnt = y;
+        for dp_i in dp.iter() {
+            if (cnt & 1) != 0 {
+                cur = dp_i[cur];
+            }
+            cnt >>= 1;
+        }
+        println!("{}", cur + 1);
+    }
 }