Interleaving String

Medium 30 pts New · no attempts yet csharp

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Interleaving String — DoorDash interview prep · 2-D Dynamic Programming

Classic interview problem #97.

Input (stdin)

Line 1: m\nLine 2: n

Output (stdout)

DP 2D grid paths (Interleaving String)

Your program must read from stdin and write the answer to stdout (no extra debug text).

Examples

Sample

Input

3
7

Output

Static hints

Input format: Line 1: m\nLine 2: n
DSA Interview 150 — 2-D Dynamic Programming
Problem #97
Frequently asked at DoorDash
2-D Dynamic Programming

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Your solution

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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

class Program
{
    static int[] Ria(string line = null)
    {
        line ??= Console.ReadLine();
        if (string.IsNullOrWhiteSpace(line)) return Array.Empty<int>();
        return line.Trim().Split(new[] { ' ', ',', '\t' }, StringSplitOptions.RemoveEmptyEntries)
            .Select(int.Parse).ToArray();
    }
    static string[] Rsa()
    {
        int n = int.Parse(Console.ReadLine());
        var arr = new string[n];
        for (int i = 0; i < n; i++) arr[i] = Console.ReadLine();
        return arr;
    }
    static void W(params object[] parts) => Console.WriteLine(string.Join(" ", parts));
    static void Wb(bool v) => Console.WriteLine(v ? "true" : "false");
    static void Wi(int v) => Console.WriteLine(v);
    static void Ws(string v) => Console.WriteLine(v);

static void Main()
    {
        // Read from stdin (see problem statement for format)
        // Line 1: m\nLine 2: n

}
}

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Official solution

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

class Program
{
    static int[] Ria(string line = null)
    {
        line ??= Console.ReadLine();
        if (string.IsNullOrWhiteSpace(line)) return Array.Empty<int>();
        return line.Trim().Split(new[] { ' ', ',', '\t' }, StringSplitOptions.RemoveEmptyEntries)
            .Select(int.Parse).ToArray();
    }
    static string[] Rsa()
    {
        int n = int.Parse(Console.ReadLine());
        var arr = new string[n];
        for (int i = 0; i < n; i++) arr[i] = Console.ReadLine();
        return arr;
    }
    static void W(params object[] parts) => Console.WriteLine(string.Join(" ", parts));
    static void Wb(bool v) => Console.WriteLine(v ? "true" : "false");
    static void Wi(int v) => Console.WriteLine(v);
    static void Ws(string v) => Console.WriteLine(v);

    static void Main()
    {
int m = int.Parse(Console.ReadLine());
int n = int.Parse(Console.ReadLine());
int[] dp = new int[n];
Array.Fill(dp, 1);
for (int i = 1; i < m; i++)
    for (int j = 1; j < n; j++)
        dp[j] += dp[j - 1];
Wi(dp[n - 1]);
    }
}

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Explanation

Step 1 / 1

DoorDash interview context: Interleaving String is a Medium 2-D Dynamic Programming problem — Grid DP: dp[row][col] often means paths or min cost to reach a cell.

Use the animation above to step through each move before writing code.

Pattern: 2-D Dynamic Programming

Read from stdin, write to stdout. Classic interview problem #97.

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