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| 1 | +# 0011 DNA_Matching ( L-I ) |
| 2 | + |
| 3 | +## Problem |
| 4 | + |
| 5 | +You are given two DNA sequences as strings, representing the genetic code of two individuals. Each DNA sequence consists of a series of characters, where each character can be one of four options: 'A' (adenine), 'C' (cytosine), 'G' (guanine), or 'T' (thymine). |
| 6 | + |
| 7 | +Write a JavaScript function called dnaMatch that takes these two DNA sequences as input and returns true if they are a match and false otherwise. Two DNA sequences are considered a match if they have the same characters in the same order. |
| 8 | + |
| 9 | +**Example** |
| 10 | + |
| 11 | +``` |
| 12 | +If the input DNA sequences are "ACGT" and "ACGT", the function should return true because they are an exact match. |
| 13 | +If the input DNA sequences are "ACGT" and "ACTG", the function should return false because the order of characters is different. |
| 14 | +If the input DNA sequences are "AACT" and "AACC", the function should return true because some characters do not match. |
| 15 | +``` |
| 16 | + |
| 17 | +**Here's an example of how the function should work:** |
| 18 | + |
| 19 | +```javascript |
| 20 | +console.log(dnaMatch("ACGT", "ACGT")); // true |
| 21 | +console.log(dnaMatch("ACGT", "ACTG")); // false |
| 22 | +console.log(dnaMatch("AACT", "AACC")); // false |
| 23 | +``` |
| 24 | + |
| 25 | +## Solutions |
| 26 | + |
| 27 | +```javascript |
| 28 | +function dnaMatch(dna1, dna2) { |
| 29 | + // Check if the lengths of the two DNA sequences are different |
| 30 | + if (dna1.length !== dna2.length) { |
| 31 | + return false; // Different lengths, not a match |
| 32 | + } |
| 33 | + |
| 34 | + // Iterate through each character of the DNA sequences |
| 35 | + for (let i = 0; i < dna1.length; i++) { |
| 36 | + // Compare characters at the current position |
| 37 | + if (dna1[i] !== dna2[i]) { |
| 38 | + return false; // Characters don't match, not a match |
| 39 | + } |
| 40 | + } |
| 41 | + |
| 42 | + // If we reach this point, all characters match, so it's a match |
| 43 | + return true; |
| 44 | +} |
| 45 | + |
| 46 | +// Test cases |
| 47 | +console.log(dnaMatch("ACGT", "ACGT")); // true |
| 48 | +console.log(dnaMatch("ACGT", "ACTG")); // false |
| 49 | +console.log(dnaMatch("AACT", "AACC")); // false |
| 50 | +``` |
| 51 | + |
| 52 | +## How it works |
| 53 | + |
| 54 | +1. The `dnaMatch` function takes two input arguments: `dna1` and `dna2`, which are the two DNA sequences we want to compare. |
| 55 | + |
| 56 | +2. First, it checks if the lengths of `dna1` and `dna2` are different using the `if (dna1.length !== dna2.length)` conditional statement. If they have different lengths, the function immediately returns `false` because sequences of different lengths cannot be a match. |
| 57 | + |
| 58 | +3. If the lengths are the same, the function proceeds to compare the characters of the two DNA sequences. |
| 59 | + |
| 60 | +4. It enters a `for` loop that iterates through the characters of the sequences. The loop is controlled by the variable `i`, which starts at 0 and goes up to `dna1.length - 1`. This loop allows us to compare characters at the same position in both sequences. |
| 61 | + |
| 62 | +5. Inside the loop, the code compares the characters at the current position `i` using the conditional statement `if (dna1[i] !== dna2[i])`. If the characters at position `i` are not the same in both sequences, the function immediately returns `false` because it found a mismatch. |
| 63 | + |
| 64 | +6. If the loop completes without finding any mismatches, meaning it has compared all characters in both sequences, the function returns `true`. This indicates that the two DNA sequences are identical and, therefore, a match. |
| 65 | + |
| 66 | +## References |
| 67 | + |
| 68 | +- [ChatGPT](https://chat.openai.com/) |
| 69 | + |
| 70 | +## Problem Added By |
| 71 | + |
| 72 | +- [Tipchan](https://github.com/tsongtheng) |
| 73 | + |
| 74 | +## Contributing |
| 75 | + |
| 76 | +Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change. |
| 77 | + |
| 78 | +Please make sure to update tests as appropriate. |
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