docs: update readme to lc problem: No.0177 (doocs#592)

No.0177.Nth Highest Salary

Author: gsbabil

solution/0100-0199/0177.Nth Highest Salary/README_EN.md

@@ -6,48 +6,31 @@
 
 <p>Write a SQL query to get the <em>n</em><sup>th</sup> highest salary from the <code>Employee</code> table.</p>
 
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 <pre>
 
 +----+--------+
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 | Id | Salary |
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 +----+--------+
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 | 1  | 100    |
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 | 2  | 200    |
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 | 3  | 300    |
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 +----+--------+
 
 </pre>
 
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 <p>For example, given the above Employee table, the <em>n</em><sup>th</sup> highest salary where <em>n</em> = 2 is <code>200</code>. If there is no <em>n</em><sup>th</sup> highest salary, then the query should return <code>null</code>.</p>
 
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 <pre>
 
 +------------------------+
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 | getNthHighestSalary(2) |
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 +------------------------+
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 | 200                    |
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 +------------------------+
 
 </pre>
 
 
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 ## Solutions
 
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