55 lines
903 B
Rust
55 lines
903 B
Rust
/**
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* [202] Happy Number
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*/
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pub struct Solution {}
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// submission codes start here
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use std::{collections::HashSet, ops::Add};
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impl Solution {
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pub fn is_happy(n: i32) -> bool {
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let mut s = HashSet::new();
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let mut n = Solution::calculate_square(n);
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while n != 1 {
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dbg!(n);
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if s.contains(&n) {
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return false;
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}
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s.insert(n);
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n = Solution::calculate_square(n);
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}
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true
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}
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fn calculate_square(n: i32) -> i32 {
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let mut n = n;
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let mut result = 0;
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while n != 0 {
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result += (n % 10).pow(2);
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n = n / 10;
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}
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result
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}
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}
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// submission codes end
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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 test_202() {
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assert!(Solution::is_happy(19));
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assert!(!Solution::is_happy(2));
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}
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}
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