tessoku-book/c07

tessoku-book/src/bin/c07.rs

@@ -8,9 +8,53 @@ use proconio::marker::*;
 #[allow(unused_imports)]
 use std::collections::*;
 
+pub fn bsearch<F>(ok: i64, ng: i64, pred: F) -> Option<i64>
+where
+    F: Fn(i64) -> bool,
+{
+    let orig_ok = ok;
+    let mut ok = ok;
+    let mut ng = ng;
+    while (ok - ng).abs() > 1 {
+        let mid = (ok + ng) / 2;
+        if pred(mid) {
+            ok = mid;
+        } else {
+            ng = mid;
+        }
+    }
+    if ok == orig_ok {
+        None
+    } else {
+        Some(ok)
+    }
+}
+
 fn solve() {
     input! {
+        n: usize,
+        mut cv: [i64; n],
+        q: usize,
+        xv: [i64; q]
     };
+
+    cv.sort();
+    let cusum = cv
+        .into_iter()
+        .scan(0_i64, |state, c| {
+            *state += c;
+            Some(*state)
+        })
+        .collect::<Vec<_>>();
+    for x in xv {
+        let res = bsearch(-1, n as i64, |i| {
+            let i = i as usize;
+            cusum[i] <= x
+        })
+        .map(|i| i + 1)
+        .unwrap_or(0);
+        println!("{}", res);
+    }
 }
 
 fn main() {