Number of Substrings With Only 1s LeetCode solution in Rust

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impl Solution {
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  pub fn num_sub(s: String) -> i32 {
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    const MODULO: i64 = 10_i64.pow(9) + 7;
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    let mut count: i64 = 0;
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    let mut temp_count_1: i64 = 0;
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    for (i, c) in s.chars().enumerate() {
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      if c != '1' {
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        count += (temp_count_1 * (temp_count_1 + 1) / 2);
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        temp_count_1 = 0;
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        continue;
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      }
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      temp_count_1 += 1;
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    }
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    count += (temp_count_1 * (temp_count_1 + 1) / 2);
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    return (count % MODULO) as i32;
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  }
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}