27 lines
761 B
Rust
27 lines
761 B
Rust
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pub fn reverse(number: i32) -> i32 {
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number
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// Convert to an absolute number without wrapping or panicking.
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.unsigned_abs()
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// Convert the number to string, then reverse all its characters.
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.to_string()
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.chars()
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.rev()
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// Collect the reversed characters back into a string.
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.collect::<String>()
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// Parse the string into an i32.
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.parse()
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// If it returns an Err then use 0 instead.
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.unwrap_or(0)
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// Then multiply by 0, 1 or -1 depending on the sign of the original number.
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* number.signum()
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}
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#[test]
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fn test_reverse_integer() {
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assert_eq!(reverse(123), 321);
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assert_eq!(reverse(-123), -321);
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assert_eq!(reverse(120), 21);
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assert_eq!(reverse(i32::MAX), 0);
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assert_eq!(reverse(i32::MIN), 0);
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}
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