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Running Sum of 1d Array - Easy - LeetCode - MiniTV

Running Sum of 1d Array - Easy - LeetCode - मिनी टीवी

Given an array nums. We define a running sum of an array as runningSum[i] = sum(nums[0]…nums[i]).

Return the running sum of nums.

 

Example 1:

Input: nums = [1,2,3,4]

Output: [1,3,6,10]

Explanation: Running sum is obtained as follows: [1, 1+2, 1+2+3, 1+2+3+4].

 

Example 2:

Input: nums = [1,1,1,1,1]

Output: [1,2,3,4,5]

Explanation: Running sum is obtained as follows: [1, 1+1, 1+1+1, 1+1+1+1, 1+1+1+1+1].

 

Example 3:

Input: nums = [3,1,2,10,1]

Output: [3,4,6,16,17]

 

Constraints:

1 <= nums.length <= 1000

-10^6 <= nums[i] <= 10^6

 

Solution:

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

namespace LeetCode.AskGif.Easy.Array
{
    public class RunningSumSoln
    {
        public int[] RunningSum(int[] nums)
        {
            var res = new int[nums.Length];
            int sum = 0;
            for (int i = 0; i < nums.Length; i++)
            {
                sum += nums[i];
                res[i] = sum;
            }

            return res;
        }
    }
}

 

Time Complexity: O(n)

Space Complexity: O(n)

 

Unit Tests:

using LeetCode.AskGif.Easy.Array;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using System;
using System.Collections.Generic;
using System.Text;

namespace CodingUnitTest.Easy.Array
{
    [TestClass]
    public class RunningSumSolnTests
    {
        [TestMethod]
        public void RunningSumSoln_First()
        {
            var nums = new[] { 1, 2, 3, 4 };
            var expected = new int[] { 1, 3, 6, 10 };

            var res = new RunningSumSoln().RunningSum(nums);
            AreEqual(expected, res);
        }

        [TestMethod]
        public void RunningSumSoln_Second()
        {
            var nums = new[] { 1, 1, 1, 1, 1 };
            var expected = new int[] { 1, 2, 3, 4, 5 };

            var res = new RunningSumSoln().RunningSum(nums);
            AreEqual(expected, res);
        }

        [TestMethod]
        public void RunningSumSoln_Third()
        {
            var nums = new[] { 3, 1, 2, 10, 1 };
            var expected = new int[] { 3, 4, 6, 16, 17 };

            var res = new RunningSumSoln().RunningSum(nums);
            AreEqual(expected, res);
        }

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

    }
}