1424. Diagonal Traverse II

public class Solution {
    public int[] FindDiagonalOrder(IList<IList<int>> nums) {
        var queue = new Queue<(int row, int col)>();
        queue.Enqueue((0, 0));
        var ans = new List<int>();
        
        while (queue.Count > 0) {
            var (row, col) = queue.Dequeue();
            ans.Add(nums[row][col]);
            
            if (col == 0 && row + 1 < nums.Count) {
                queue.Enqueue((row + 1, col));
            }
            
            if (col + 1 < nums[row].Count) {
                queue.Enqueue((row, col + 1));
            }
        }
        
        return ans.ToArray();
    }
}

#include <bits/stdc++.h>
using namespace std;

// Auto-generated C++ draft from the C# solution. Review containers, LINQ and helper types before submit.
class Solution {
public:
    public vector<int>& FindDiagonalOrder(IList<vector<int>> nums) {
        var queue = new queue<(int row, int col)>();
        queue.Enqueue((0, 0));
        var ans = new List<int>();
        
        while (queue.size() > 0) {
            var (row, col) = queue.Dequeue();
            ans.push_back(nums[row][col]);
            
            if (col == 0 && row + 1 < nums.size()) {
                queue.Enqueue((row + 1, col));
            }
            
            if (col + 1 < nums[row].size()) {
                queue.Enqueue((row, col + 1));
            }
        }
        
        return ans.ToArray();
    }
}

class Solution {
    public int[] findDiagonalOrder(List<List<Integer>> nums) {
        Queue<Pair<Integer, Integer>> queue = new LinkedList();
        queue.offer(new Pair(0, 0));
        List<Integer> ans = new ArrayList();
        
        while (!queue.isEmpty()) {
            Pair<Integer, Integer> p = queue.poll();
            int row = p.getKey();
            int col = p.getValue();
            ans.add(nums.get(row).get(col));
            
            if (col == 0 && row + 1 < nums.size()) {
                queue.offer(new Pair(row + 1, col));
            }
            
            if (col + 1 < nums.get(row).size()) {
                queue.offer(new Pair(row, col + 1));
            }
        }
        
        int[] result = new int[ans.size()];
        int i = 0;
        for (int num : ans) {
            result[i] = num;
            i++;
        }
        
        return result;
    }
}

class Solution {
    findDiagonalOrder(nums) {
        const queue = [[0, 0]];
        const ans = [];
        
        while (queue.length > 0) {
            const [row, col] = queue.shift();
            ans.push(nums[row][col]);
            
            if (col === 0 && row + 1 < nums.length) {
                queue.push([row + 1, col]);
            }
            
            if (col + 1 < nums[row].length) {
                queue.push([row, col + 1]);
            }
        }
        
        return ans;
    }
}

from collections import deque

class Solution:
    def findDiagonalOrder(self, nums: List[List[int]]) -> List[int]:
        queue = deque([(0, 0)])
        ans = []
        
        while queue:
            row, col = queue.popleft()
            ans.append(nums[row][col])
            
            if col == 0 and row + 1 < len(nums):
                queue.append((row + 1, col))
                
            if col + 1 < len(nums[row]):
                queue.append((row, col + 1))
                
        return ans

func findDiagonalOrder(nums [][]int) []int {
    queue := []struct{ row, col int }{{0, 0}}
    ans := []int{}
    
    for len(queue) > 0 {
        row, col := queue[0].row, queue[0].col
        queue = queue[1:]
        ans = append(ans, nums[row][col])
        
        if col == 0 && row + 1 < len(nums) {
            queue = append(queue, struct{ row, col int }{row + 1, col})
        }
        
        if col + 1 < len(nums[row]) {
            queue = append(queue, struct{ row, col int }{row, col + 1})
        }
    }
    
    return ans
}

Algorithm

Инициализируйте очередь с (0, 0) и список ответов ans.

Пока очередь не пуста:

Извлеките (row, col) из очереди.

Добавьте nums[row][col] в ans.

Если col == 0 и row + 1 в пределах Arrayа, добавьте (row + 1, col) в очередь.

Если col + 1 в пределах текущей строки, добавьте (row, col + 1) в очередь.

return ans.

😎