Step through the algorithm visually — use Play or the step buttons (inspired by AlgoMaster / visualgo).
Flipkart interview context: Coin Change is a Medium 1-D Dynamic Programming problem — Define state dp[i] and transition from smaller subproblems.
Use the animation above to step through each move before writing code.
Pattern: 1-D Dynamic Programming
Read from stdin, write to stdout. Classic interview problem #322.
Coin Change — Flipkart interview prep · 1-D Dynamic Programming
Classic interview problem #322.
Input (stdin)
Line 1: coins\nLine 2: amount
Output (stdout)
Min coins or -1
Your program must read from stdin and write the answer to stdout (no extra debug text).
1 2 5 11
3
| Test | Status | Details |
|---|
Ready — edit the code above and click Run or Submit.
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()
{
var coins = Ria();
int amount = int.Parse(Console.ReadLine());
int[] dp = new int[amount + 1];
Array.Fill(dp, amount + 1);
dp[0] = 0;
for (int a = 1; a <= amount; a++)
foreach (var c in coins)
if (c <= a) dp[a] = Math.Min(dp[a], dp[a - c] + 1);
Wi(dp[amount] > amount ? -1 : dp[amount]);
}
}Try solving on your own first, then reveal the official answer.