{

public int GetMinCoinsForBalance(int amount, int[] coins)

{

// create the dp array that contains the coins for 0...amount.

var dp = new int[amount + 1];

// initialize bigger value.

for(int i=0; i <= amount; i++)

{

dp[i] = amount + 1;

}

dp[0] = 0;

for (int i=0;i<= amount; i++)

{

for (int j=0; j< coins.Length; j++)

{

if (coins[j] <= i)

{

// In this case, take the min of dp[i] which is the current number of coins added so far

// and dp[i - coin[j]] which is the amount added previously plus current coin (1)

// [For instance, if the amount is 9 and if there are coins {1,6} and j=1 then dp[9-6] = dp[3] which will be 3 + 1 (current coind which is 6) = 4].

// In above case, when j=0 which is coin=1 then in first attempt the dp[9] = dp[9-1] + 1 = 9. As described above, the dp[9] will be 4.

dp[i] = Math.Min(dp[i], 1 + dp[i - coins[j]]);

}

else

{

break;

}

}

}

return dp[amount] > amount ? -1 : dp[amount];

}

public int GetCoinsForBalance(int balance, int[] coins)

{

int minValue = Int16.MaxValue;

int coinCounter = 0;

if (balance == 0) return 0;

foreach(int coin in coins)

{

if (balance - coin >= 0)

{

coinCounter = this.GetCoinsForBalance(balance - coin, coins);

if (minValue > coinCounter)

{

minValue = coinCounter;

}

}

}

return minValue + 1;

}

[TestMethod]

public void TestMinCoinChange()

{

int result = this.GetMinCoinsForBalance(19, new []{ 1, 6, 10 });

Assert.AreEqual(result, 4);

}