Given a positive integer n
, there exists a 0-indexed array called powers
, composed of the minimum number of powers of 2
that sum to n
. The array is sorted in non-decreasing order, and there is only one way to form the array.
You are also given a 0-indexed 2D integer array queries
, where queries[i] = [lefti, righti]
. Each queries[i]
represents a query where you have to find the product of all powers[j]
with lefti <= j <= righti
.
Return an arrayanswers
, equal in length toqueries
, whereanswers[i]
is the answer to theith
query. Since the answer to the ith
query may be too large, each answers[i]
should be returned modulo109 + 7
.
Input: n = 15, queries = [[0,1],[2,2],[0,3]] Output: [2,4,64] Explanation: For n = 15, powers = [1,2,4,8]. It can be shown that powers cannot be a smaller size. Answer to 1st query: powers[0] * powers[1] = 1 * 2 = 2. Answer to 2nd query: powers[2] = 4. Answer to 3rd query: powers[0] * powers[1] * powers[2] * powers[3] = 1 * 2 * 4 * 8 = 64. Each answer modulo 109 + 7 yields the same answer, so [2,4,64] is returned.
Input: n = 2, queries = [[0,0]] Output: [2] Explanation: For n = 2, powers = [2]. The answer to the only query is powers[0] = 2. The answer modulo 109 + 7 is the same, so [2] is returned.
1 <= n <= 109
1 <= queries.length <= 105
0 <= starti <= endi < powers.length
implSolution{pubfnproduct_queries(n:i32,queries:Vec<Vec<i32>>) -> Vec<i32>{letmut powers = vec![];letmut answers = vec![1_i64; queries.len()];for i in0..30{if n &(1 << i) != 0{ powers.push(1 << i);}}for i in0..queries.len(){for j in queries[i][0]asusize..=queries[i][1]asusize{ answers[i] = (answers[i]* powers[j]) % 1_000_000_007;}} answers.into_iter().map(|x| x asi32).collect()}}