126 lines
2.8 KiB
Rust
126 lines
2.8 KiB
Rust
/**
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* [2719] Count of Integers
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*/
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pub struct Solution {}
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// submission codes start here
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struct DigitDP {
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num1: Vec<u32>,
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num2: Vec<u32>,
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min_sum: u32,
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max_sum: u32,
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dp_vec: Vec<Vec<i32>>,
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}
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impl DigitDP {
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pub fn new(num1: Vec<u32>, num2: Vec<u32>, min_sum: u32, max_sum: u32) -> DigitDP {
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let mut dp = Vec::with_capacity(num2.len());
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for _ in 0..num2.len() {
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let length = num2.len() * 9 + 1;
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let mut array = Vec::with_capacity(length);
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array.resize(length, -1);
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dp.push(array)
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}
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DigitDP {
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num1,
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num2,
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min_sum,
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max_sum,
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dp_vec: dp,
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}
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}
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pub fn dp(&mut self, sum: u32, l_limit: bool, r_limit: bool, index: usize) -> i32 {
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if index >= self.num2.len() {
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return if sum >= self.min_sum && sum <= self.max_sum {
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1
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} else {
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0
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};
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}
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if !l_limit && !r_limit && self.dp_vec[index][sum as usize] != -1 {
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return self.dp_vec[index][sum as usize];
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}
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let low = if l_limit { self.num1[index] } else { 0 };
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let high = if r_limit { self.num2[index] } else { 9 };
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let mut result = 0;
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for i in low..=high {
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result += DigitDP::dp(
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self,
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sum + i,
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i == self.num1[index] && l_limit,
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i == self.num2[index] && r_limit,
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index + 1,
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);
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if result > 1000000007 {
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result = result % 1000000007
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}
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}
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if !l_limit && !r_limit {
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self.dp_vec[index][sum as usize] = result;
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}
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result
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}
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}
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impl Solution {
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pub fn count(num1: String, num2: String, min_sum: i32, max_sum: i32) -> i32 {
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let mut num1 = Solution::str_to_vec(num1);
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let num2 = Solution::str_to_vec(num2);
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// 将两个数组的长度对齐，在num1前面填0
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for _ in 0..(num2.len() - num1.len()) {
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num1.insert(0, 0);
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}
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let mut digit_dp = DigitDP::new(num1, num2, min_sum as u32, max_sum as u32);
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digit_dp.dp(0, true, true, 0)
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}
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fn str_to_vec(num: String) -> Vec<u32> {
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let mut num_vec = Vec::new();
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for c in num.chars() {
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match c.to_digit(10) {
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None => {}
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Some(i) => num_vec.push(i),
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}
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}
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num_vec
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}
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}
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// submission codes end
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn test_2719() {
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assert_eq!(
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Solution::count(String::from("1"), String::from("12"), 1, 8),
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11
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);
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assert_eq!(
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Solution::count(String::from("1"), String::from("5"), 1, 5),
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5
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);
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}
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}
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