Rust每日一练(Leetday0030) 合并有序数组、格雷编码、子集II

fn merge(nums1: &mut Vec<i32>, m: i32, nums2: &Vec<i32>, n: i32) {
    let nums: Vec<i32> = nums1[..m as usize].to_vec(); // 复制nums1中的前m个元素到新数组中
    let (mut p1, mut p2) = (0, 0); // 双指针遍历nums1和nums2，将较小的元素放入nums1中
    for i in 0..(m + n) as usize {
        if p1 >= m as usize {
            nums1[i] = nums2[p2];
            p2 += 1;
        } else if p2 >= n as usize {
            nums1[i] = nums[p1];
            p1 += 1;
        } else if nums[p1] <= nums2[p2] {
            nums1[i] = nums[p1];
            p1 += 1;
        } else {
            nums1[i] = nums2[p2];
            p2 += 1;
        }
    }
}
fn main() {
    let mut nums1 = vec![1, 2, 3, 0, 0, 0];
    let nums2 = vec![2, 5, 6];
    let m = 3;
    let n = 3;
    merge(&mut nums1, m, &nums2, n);
    println!("{:?}", nums1);
}

fn merge(nums1: &mut Vec<i32>, m: i32, nums2: &Vec<i32>, n: i32) {
    let mut p1 = m - 1;
    let mut p2 = n - 1;
    let mut i = m + n - 1;
    while i >= 0 {
        if p1 < 0 {
            nums1[i as usize] = nums2[p2 as usize];
            p2 -= 1;
        } else if p2 < 0 {
            nums1[i as usize] = nums1[p1 as usize];
            p1 -= 1;
        } else if nums1[p1 as usize] >= nums2[p2 as usize] {
            nums1[i as usize] = nums1[p1 as usize];
            p1 -= 1;
        } else {
            nums1[i as usize] = nums2[p2 as usize];
            p2 -= 1;
        }
        i -= 1;
    }
}
fn main() {
    let mut nums1 = vec![1, 2, 3, 0, 0, 0];
    let nums2 = vec![2, 5, 6];
    let m = 3;
    let n = 3;
    merge(&mut nums1, m, &nums2, n);
    println!("{:?}", nums1); // [1, 2, 2, 3, 5, 6]
}

fn gray_code(n: u32) -> Vec<i32> {
    let l = 1 << n;
    let mut res: Vec<i32> = vec![0; l as usize];
    for i in 0..l {
        res[i as usize] = ((i >> 1) ^ i) as i32;
    }
    res
}
fn main() {
    println!("{:?}", gray_code(2));
    println!("{:?}", gray_code(1));

fn subsets_with_dup(nums: &mut Vec<i32>) -> Vec<Vec<i32>> {
    nums.sort();
    let mut res: Vec<Vec<i32>> = vec![];
    for k in 0..=nums.len() {
        let mut c: Vec<i32> = vec![];
        generate_subsets_with_dup(nums, k, 0, &mut c, &mut res);
    }
    res
}
fn generate_subsets_with_dup(nums: &Vec<i32>, k: usize, start: usize, c: &mut Vec<i32>, res: &mut Vec<Vec<i32>>) {
    if c.len() == k {
        let b: Vec<i32> = c.to_vec();
        res.push(b);
        return;
    }
    for i in start..(nums.len() - (k - c.len()) + 1) {
        if i > start && nums[i] == nums[i - 1] {
            continue;
        }
        c.push(nums[i]);
        generate_subsets_with_dup(nums, k, i + 1, c, res);
        c.pop();
    }
}
fn main() {
    let mut nums: Vec<i32> = vec![1, 2, 2];
    let res = subsets_with_dup(&mut nums);
    println!("{:?}", res);
}