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
function solveEquation(equation: string): string {
    const [left, right] = equation.split('=');
    const createExpr = (s: string) => {
        let x = 0;
        let n = 0;
        let i = 0;
        let sym = 1;
        let cur = 0;
        let isX = false;
        for (const c of s) {
            if (c === '+' || c === '-') {
                if (isX) {
                    if (i === 0 && cur === 0) {
                        cur = 1;
                    }
                    x += cur * sym;
                } else {
                    n += cur * sym;
                }
                isX = false;
                cur = 0;
                i = 0;
                if (c === '+') {
                    sym = 1;
                } else {
                    sym = -1;
                }
            } else if (c === 'x') {
                isX = true;
            } else {
                i++;
                cur *= 10;
                cur += Number(c);
            }
        }
        if (isX) {
            if (i === 0 && cur === 0) {
                cur = 1;
            }
            x += cur * sym;
        } else {
            n += cur * sym;
        }
        return [x, n];
    };
    const lExpr = createExpr(left);
    const rExpr = createExpr(right);
    if (lExpr[0] === rExpr[0]) {
        if (lExpr[1] !== rExpr[1]) {
            return 'No solution';
        }
        return 'Infinite solutions';
    }
    return `x=${(lExpr[1] - rExpr[1]) / (rExpr[0] - lExpr[0])}`;
}
