Greetings! Today, you will delve into handling and manipulating strings in C++, a piece of fundamental knowledge in many areas of programming. Specifically, we'll learn how to identify consecutive groups of identical characters in a string. Intrigued to enhance your skills? Without further ado, let's proceed!
In this lesson, your objective is to write a C++ function that accepts a string as input and identifies all consecutive groups of identical characters within it. A group is defined as a segment of the text wherein the same character is repeated consecutively.
Your function should return a vector of pairs. Each pair will consist of the repeating character and the length of its repetition. For example, if the input string is "aaabbcccaae", your function should output: 'a':3, 'b':2, 'c':3, 'a':2, 'e':1.
Bear in mind that, while processing the input string, we are interested only in alphanumeric characters (i.e., alphabets and digits), without differentiating the case. Other characters present will not factor into the formation of these groups.
Ready to discover how to accomplish this task? Let's set forth!
When aiming to solve a problem, it's always crucial to first establish our scope by taking preliminary steps. First, we will initialize an empty vector groups to store our results. We will also declare two variables, current_group_char and current_group_length, which will help us monitor the character of the current group and the length of its consecutive sequence.
C++1// Function to find consecutive character groups in a string 2std::vector<std::pair<char, int>> solution(std::string s) { 3 std::vector<std::pair<char, int>> groups; // Vector to store the groups of characters 4 char current_group_char = '\0'; // Variable to hold the current character group 5 int current_group_length = 0; // Variable to hold the length of the current character group 6}
With the setup in place, we are now ready for the main game: processing the input string. For this, we'll create a loop to examine each character. At every step, the character is checked to see if it is alphanumeric as that is our primary interest.
C++1// Function to find consecutive character groups in a string 2std::vector<std::pair<char, int>> solution(std::string s) { 3 std::vector<std::pair<char, int>> groups; // Vector to store the groups of characters 4 char current_group_char = '\0'; // Variable to hold the current character group 5 int current_group_length = 0; // Variable to hold the length of the current character group 6 for(char &c: s){ 7 if(isalnum(c)){ // Check if the character is alphanumeric 8 } 9 } 10}
As the loop executes, if a character is the same as current_group_char, it implies that the group is continuing, and we simply increment current_group_length. However, if the character differs from current_group_char, it signals the start of a new group.
At the start of a new group, we will push the pair (current_group_char, current_group_length) to groups, and then update current_group_char and current_group_length with the new character and 1, respectively.
C++1// Function to find consecutive character groups in a string 2std::vector<std::pair<char, int>> solution(std::string s) { 3 std::vector<std::pair<char, int>> groups; // Vector to store the groups of characters 4 char current_group_char = '\0'; // Variable to hold the current character group 5 int current_group_length = 0; // Variable to hold the length of the current character group 6 7 for(char &c: s){ 8 if(isalnum(c)){ // Check if the character is alphanumeric 9 if(c == current_group_char){ // If the character is part of the current group 10 current_group_length += 1; // Increment the length of the current group 11 } else { // If the character starts a new group 12 if(current_group_char != '\0'){ // Push the previous group to groups if it exists 13 groups.push_back(std::make_pair(current_group_char, current_group_length)); 14 } 15 current_group_char = c; // Update the current character to the new group 16 current_group_length = 1; // Reset the length for the new group 17 } 18 } 19 } 20}
After the loop ends, it's important to acknowledge any leftover group that may not yet be added to groups. This can happen because a group is only added to groups when we identify a new group. To ensure we don't miss any groups, we perform a final check on current_group_char and if needed, add it to groups.
C++1#include <iostream> 2#include <vector> 3#include <cctype> 4 5// Function to find consecutive character groups in a string 6std::vector<std::pair<char, int>> solution(std::string s) { 7 std::vector<std::pair<char, int>> groups; // Vector to store the groups of characters 8 char current_group_char = '\0'; // Variable to hold the current character group 9 int current_group_length = 0; // Variable to hold the length of the current character group 10 11 for(char &c: s){ 12 if(isalnum(c)){ // Check if the character is alphanumeric 13 if(c == current_group_char){ // If the character is part of the current group 14 current_group_length += 1; // Increment the length of the current group 15 } else { // If the character starts a new group 16 if(current_group_char != '\0'){ // Push the previous group to groups if it exists 17 groups.push_back(std::make_pair(current_group_char, current_group_length)); 18 } 19 current_group_char = c; // Update the current character to the new group 20 current_group_length = 1; // Reset the length for the new group 21 } 22 } 23 } 24 if(current_group_char != '\0'){ // Add the last group if it exists 25 groups.push_back(std::make_pair(current_group_char, current_group_length)); 26 } 27 28 return groups; // Return the vector of groups 29}
Congratulations! You have now learned how to identify consecutive groups of characters in a string using C++. This skill can come in handy when analyzing text-related problems or even when preprocessing data for machine learning. To improve your grasp on the subject, you should practice similar problems. Always remember, proficiency comes through persistence and consistent effort. Now, it's time to get started with those strings!