use vstd::prelude::*; fn main() {} verus! { pub struct Solution; pub open spec fn sum_range(a: Seq, l: int, r: int) -> int recommends 0 <= l <= r <= a.len(), decreases r - l, { if l >= r { 0int } else { a[l] as int + sum_range(a, l + 1, r) } } impl Solution { pub fn odd_queries( a: Vec, n: usize, ls: Vec, rs: Vec, ks: Vec, q: usize, ) -> (result: Vec) requires 1 <= n <= 200_000, 1 <= q <= 200_000, a.len() == n, ls.len() == q, rs.len() == q, ks.len() == q, forall|i: int| 0 <= i < a.len() ==> 1 <= #[trigger] a[i] <= 1_000_000_000, forall|i: int| 0 <= i < ls.len() ==> 1 <= #[trigger] ls[i] && ls[i] as int <= rs[i] as int && rs[i] as int <= n as int, forall|i: int| 0 <= i < rs.len() ==> 1 <= #[trigger] rs[i] && rs[i] as int <= n as int, forall|i: int| 0 <= i < ks.len() ==> 1 <= #[trigger] ks[i] <= 1_000_000_000, ensures result.len() == q, forall|i: int| 0 <= i < q ==> #[trigger] result[i] == ( (sum_range(a@, 0, ls[i] as int - 1) + ks[i] as int * (rs[i] as int - ls[i] as int + 1) + sum_range(a@, rs[i] as int, n as int)) % 2 == 1 ), { let mut prefix: Vec = Vec::with_capacity(n + 1); prefix.push(0i64); let mut s: i64 = 0; let mut i: usize = 0; while i < n { s += a[i] as i64; prefix.push(s); i += 1; } let pref_n: i64 = prefix[n]; let mut result: Vec = Vec::with_capacity(q); let mut j: usize = 0; while j < q { let l = ls[j] as usize; let r = rs[j] as usize; let k_val = ks[j] as i64; let count: i64 = (r - l + 1) as i64; let pref_l_minus_1 = prefix[l - 1]; let pref_r_v = prefix[r]; let outside: i64 = pref_l_minus_1 + (pref_n - pref_r_v); let mid: i64 = k_val * count; let total: i64 = outside + mid; let answer: bool = total % 2 == 1; result.push(answer); j += 1; } result } } }