Rust Function: Find smallest string

Last update on December 21 2024 10:18:30 (UTC/GMT +8 hours)

Write a Rust function that takes two string references and returns the smallest one.

Sample Solution:

Rust Code:

// Define a function named 'find_smallest' that takes two string references 'str1' and 'str2'
fn find_smallest<'a>(str1: &'a str, str2: &'a str) -> &'a str {
    // Check if 'str1' is less than 'str2' lexicographically
    // If it is, return 'str1', otherwise return 'str2'
    if str1 < str2 {
        str1
    } else {
        str2
    }
}

fn main() {
    // Define two string variables
    let string1 = "abc";
    let string2 = "abcd";

    // Call the 'find_smallest' function and pass the string references
    let smallest = find_smallest(&string1, &string2);

    // Print the smallest string
    println!("The smallest string is: {}", smallest);
}

Output:

The smallest string is: abc

Explanation:

Here's a brief explanation of the above Rust code:

• fn find_smallest<'a>(str1: &'a str, str2: &'a str) -> &'a str { ... }: This line defines a function named "find_smallest()" that takes two string references 'str1' and 'str2' as input parameters and returns a string reference. The lifetime 'a ensures that the returned reference lives at least as long as the input reference.
• if str1 < str2 { ... } else { ... }: This line checks if 'str1' is lexicographically less than 'str2'. If it is, 'str1' is returned; otherwise, 'str2' is returned. This comparison is based on lexicographical ordering, where shorter strings are considered smaller, and if two strings have the same prefix, the one with the smaller suffix is considered smaller.
• let smallest = find_smallest(&string1, &string2);: This line calls the "find_smallest()" function and passes references to the two string variables 'string1' and 'string2'.
• println!("The smallest string is: {}", smallest);: This line prints the smallest string returned by the "find_smallest()" function.

Rust Code Editor:

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