Consecutive Characters

Given a string s, the power of the string is the maximum length of a non-empty substring that contains only one unique character.

Return the power of the string.

Example 1:

Input: s = "leetcode"

Output: 2

Explanation: The substring "ee" is of length 2 with the character 'e' only.

Example 2:

Input: s = "abbcccddddeeeeedcba"

Output: 5

Explanation: The substring "eeeee" is of length 5 with the character 'e' only.

Example 3:

Input: s = "triplepillooooow"

Output: 5

Example 4:

Input: s = "hooraaaaaaaaaaay"

Output: 11

Example 5:

Input: s = "tourist"

Output: 1

Constraints:

1 <= s.length <= 500

s contains only lowercase English letters.

Solution:

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

namespace LeetCode.AskGif.Easy.String
{
 public class MaxPowerSoln
 {
 public int MaxPower(string s)
 {
 if (s.Length == 0) return 0;

 int max = 1;
 int count = 1;
 for(int i=1; i<s.Length; i++)
 {
 if (s[i - 1] == s[i])
 {
 count++;
 }
 else
 {
 if(count>max)
 {
 max = count;
 }
 count = 1;
 }
 }

 if (count > max)
 {
 max = count;
 }

 return max;
 }
 }
}

Time Complexity: O(n)

Space Complexity: O(1)

Unit Tests:

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

namespace CodingUnitTest.Easy.String
{
 [TestClass]
 public class MaxPowerSolnTests
 {
 [TestMethod]
 public void MaxPowerSoln_First()
 {
 var s = "leetcode"; 
 var output = 2;
 var res = new MaxPowerSoln().MaxPower(s);

 Assert.AreEqual(res, output);
 }

 [TestMethod]
 public void MaxPowerSoln_Second()
 {
 var s = "abbcccddddeeeeedcba";
 var output = 5;
 var res = new MaxPowerSoln().MaxPower(s);

 Assert.AreEqual(res, output);
 }

 [TestMethod]
 public void MaxPowerSoln_Third()
 {
 var s = "triplepillooooow";
 var output = 5;
 var res = new MaxPowerSoln().MaxPower(s);

 Assert.AreEqual(res, output);
 }

 [TestMethod]
 public void MaxPowerSoln_Fourth()
 {
 var s = "hooraaaaaaaaaaay";
 var output = 11;
 var res = new MaxPowerSoln().MaxPower(s);

 Assert.AreEqual(res, output);
 }

 [TestMethod]
 public void MaxPowerSoln_Fifth()
 {
 var s = "tourist";
 var output = 1;
 var res = new MaxPowerSoln().MaxPower(s);

 Assert.AreEqual(res, output);
 }

 [TestMethod]
 public void MaxPowerSoln_Sixth()
 {
 var s = "cc";
 var output = 2;
 var res = new MaxPowerSoln().MaxPower(s);

 Assert.AreEqual(res, output);
 }
 }
}