Kth Smallest Number in Multiplication Table LeetCode solution in Java

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class Solution {
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  public int findKthNumber(int m, int n, int k) {
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    int lo = 1;
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    int hi = m * n;
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    while (lo < hi) {
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      int mid = lo + (hi - lo) / 2;
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      if (count(mid, m, n) < k) {
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        lo = mid + 1;
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      } else if (count(mid, m, n) >= k) {
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        hi = mid;
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      }
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    }
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    return lo;
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  }
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  private int count(int mid, int m, int n) {
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    int ans = 0;
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    for (int i = 1; i <= m; i++) {
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      int res = Math.min(mid / i, n);
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      ans += res;
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    }
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    return ans;
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  }
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}