#longest common prefix

12 messages · Page 1 of 1 (latest)

grand mist
# 
class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        for (int i = 0; i < strs.size(); i++) {
            for (int j = 0; j < strs[i].size(); j++) {
                if (strs[i][j] == strs[i + 1][j + 1]) {
                    // return the letters or add them to something and return that idk
                }
            }
        }
    }
};``` I'm a beginner in C++ and I'm attempting this question, and I don't event know if the code above is correct. I'm trying to loop through the individual letters of a string in vector and compare them with the next to see if they are the same to find the longest prefix. I'm also not sure how to make it so that it discards it if its not in a row.

any help would be appreciated
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echo minnowBOT
#

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grand mist
#

question for refrence^

devout oracle
#

;compile cpp

#include <iostream>
#include <vector>
#include <string>

std::string longestCommonPrefix(std::vector<std::string>& strs) {
    if (strs.empty()) {
        return "";
    }

    // Start with the first string as the prefix candidate
    std::string prefix = strs[0];

    for (int i = 1; i < strs.size(); ++i) {
        int j = 0;
        while (j < prefix.length() && j < strs[i].length() && prefix[j] == strs[i][j]) {
            ++j;
        }
        prefix = prefix.substr(0, j); // Update the prefix
    }

    return prefix;
}

int main() {
    std::vector<std::string> strings[2] = {{"flower", "flow", "flight"}, {"dog", "racecar", "car"}};
    std::string result1 = longestCommonPrefix(strings[0]);
    std::cout << "Longest common prefix: " << result1 << std::endl;
   std::string result2 =
longestCommonPrefix(strings[1]);
    std::cout << "Longest common prefix: " << result2 << std::endl;
    return 0;
}```
frigid geodeBOT
#
Program Output
Longest common prefix: fl
Longest common prefix:
µBrain#6100 | 70ms | c++ | x86-64 gcc 13.2 | godbolt.org
grand mist
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woah

grand mist
#

@devout oracle how did you make it so that it updates if the common letters appear in a row?

devout oracle
grand mist
#

oh

#

ive never seen .substr() before

devout oracle
#

++gone kekw