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51 lines
1.2 KiB
51 lines
1.2 KiB
# 寻找完美数
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```rust
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pub fn is_perfect_number(num: usize) -> bool {
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let mut sum = 0;
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for i in 1..num - 1 {
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if num % i == 0 {
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sum += i;
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}
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}
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num == sum
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}
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pub fn perfect_numbers(max: usize) -> Vec<usize> {
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let mut result: Vec<usize> = Vec::new();
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// It is not known if there are any odd perfect numbers, so we go around all the numbers.
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for i in 1..max + 1 {
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if is_perfect_number(i) {
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result.push(i);
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}
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}
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result
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn basic() {
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assert_eq!(is_perfect_number(6), true);
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assert_eq!(is_perfect_number(28), true);
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assert_eq!(is_perfect_number(496), true);
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assert_eq!(is_perfect_number(8128), true);
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assert_eq!(is_perfect_number(5), false);
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assert_eq!(is_perfect_number(86), false);
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assert_eq!(is_perfect_number(497), false);
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assert_eq!(is_perfect_number(8120), false);
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assert_eq!(perfect_numbers(10), vec![6]);
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assert_eq!(perfect_numbers(100), vec![6, 28]);
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assert_eq!(perfect_numbers(496), vec![6, 28, 496]);
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assert_eq!(perfect_numbers(1000), vec![6, 28, 496]);
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}
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}
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``` |