Solve the Equation
<p>Solve a given equation and return the value of <code>&#39;x&#39;</code> in the form of a string <code>&quot;x=#value&quot;</code>. The equation contains only <code>&#39;+&#39;</code>, <code>&#39;-&#39;</code> operation, the variable <code>&#39;x&#39;</code> and its coefficient. You should return <code>&quot;No solution&quot;</code> if there is no solution for the equation, or <code>&quot;Infinite solutions&quot;</code> if there are infinite solutions for the equation.</p>

<p>If there is exactly one solution for the equation, we ensure that the value of <code>&#39;x&#39;</code> is an integer.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> equation = &quot;x+5-3+x=6+x-2&quot;
<strong>Output:</strong> &quot;x=2&quot;
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> equation = &quot;x=x&quot;
<strong>Output:</strong> &quot;Infinite solutions&quot;
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> equation = &quot;2x=x&quot;
<strong>Output:</strong> &quot;x=0&quot;
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>3 &lt;= equation.length &lt;= 1000</code></li>
	<li><code>equation</code> has exactly one <code>&#39;=&#39;</code>.</li>
	<li><code>equation</code> consists of integers with an absolute value in the range <code>[0, 100]</code> without any leading zeros, and the variable <code>&#39;x&#39;</code>.</li>
	<li>The input is generated that if there is a single solution, it will be an integer.</li>
</ul>
Math; String; Simulation
class Solution:
    def solveEquation(self, equation: str) -> str:
        def f(s):
            x = y = 0
            if s[0] != '-':
                s = '+' + s
            i, n = 0, len(s)
            while i < n:
                sign = 1 if s[i] == '+' else -1
                i += 1
                j = i
                while j < n and s[j] not in '+-':
                    j += 1
                v = s[i:j]
                if v[-1] == 'x':
                    x += sign * (int(v[:-1]) if len(v) > 1 else 1)
                else:
                    y += sign * int(v)
                i = j
            return x, y

        a, b = equation.split('=')
        x1, y1 = f(a)
        x2, y2 = f(b)
        if x1 == x2:
            return 'Infinite solutions' if y1 == y2 else 'No solution'
        return f'x={(y2 - y1) // (x1 - x2)}'
