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### by Sumit Chourasia | Jun 21, 2020 | Category :coding | Tags : आसानarrayडेटा-संरचनाleetcodec-sharpalgorithm

#### Add to Array-Form of Integer - Easy - LeetCode - मिनी टीवी

For a non-negative integer X, the array-form of X is an array of its digits in left to right order.  For example, if X = 1231, then the array form is [1,2,3,1].

Given the array-form A of a non-negative integer X, return the array-form of the integer X+K.

Example 1:

Input: A = [1,2,0,0], K = 34

Output: [1,2,3,4]

Explanation: 1200 + 34 = 1234

Example 2:

Input: A = [2,7,4], K = 181

Output: [4,5,5]

Explanation: 274 + 181 = 455

Example 3:

Input: A = [2,1,5], K = 806

Output: [1,0,2,1]

Explanation: 215 + 806 = 1021

Example 4:

Input: A = [9,9,9,9,9,9,9,9,9,9], K = 1

Output: [1,0,0,0,0,0,0,0,0,0,0]

Explanation: 9999999999 + 1 = 10000000000

Note：

1 <= A.length <= 10000

0 <= A[i] <= 9

0 <= K <= 10000

If A.length > 1, then A[0] != 0

Solution:

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

{
{
public IList<int> AddToArrayForm(int[] A, int K)
{
var res = new List<int>();
int i = A.Length - 1;
int carry = 0;
int a = 0;
int b = 0;
int num = 0;
while (true)
{
a = 0;
b = 0;

if (i < 0 && K <= 0)
{
break;
}

if (i >= 0)
{
a = A[i];
}
i--;

if (K > 0)
{
b = K % 10;
K = K / 10;
}

num = a + b + carry;
if (num > 9)
{
carry = num / 10;
}
else
{
carry = 0;
}
}

if(carry > 0)
{
}

res.Reverse();

return res;
}
}
}

Time Complexity: O(n)

Space Complexity: O(n) to store the result.

Unit Tests:

using Microsoft.VisualStudio.TestTools.UnitTesting;
using System;
using System.Collections.Generic;
using System.Text;

namespace CodingUnitTest.Easy.Array
{
[TestClass]
{
[TestMethod]
{
var arr = new int[] { 1, 2, 0, 0 };
var K = 34;
var expected = new int[] { 1, 2, 3, 4 };

AreEqual(expected, res);
}

[TestMethod]
{
var arr = new int[] { 2, 7, 4 };
var K = 181;
var expected = new int[] { 4, 5, 5 };

AreEqual(expected, res);
}

[TestMethod]
{
var arr = new int[] { 2, 1, 5 };
var K = 806;
var expected = new int[] { 1, 0, 2, 1 };

AreEqual(expected, res);
}

[TestMethod]
{
var arr = new int[] { 9, 9, 9, 9, 9, 9, 9, 9, 9, 9 };
var K = 1;
var expected = new int[] { 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

AreEqual(expected, res);
}

private void AreEqual(int[] res, IList<int> output)
{
Assert.AreEqual(res.Length, output.Count);
for (int i = 0; i < res.Length; i++)
{
Assert.AreEqual(res[i], output[i]);
}
}
}
}

Contributed By: Sumit Chourasia
Contributed By: Sumit Chourasia
Contributed By: Sumit Chourasia
Contributed By: Sumit Chourasia