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Consider an N-degree polynomial, expressed as follows: |
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**P**N * xN \+ **P**N-1 * xN-1 \+ ... + **P**1 * x1 \+ **P**0 * x0 |
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You'd like to find all of the polynomial's x-intercepts — in other words, all |
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distinct real values of x for which the expression evaluates to 0. |
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Unfortunately, the order of operations has been reversed: Addition (**+**) now |
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has the highest precedence, followed by multiplication (*****), followed by |
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exponentiation (**^**). In other words, an expression like ab \+ c * d should |
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be evaluated as a((b+c)*d). For our purposes, exponentiation is right- |
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associative (in other words, abc = a(bc)), and 00 = 1. The unary negation |
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operator still has the highest precedence, so the expression -2-3 * -1 + -2 |
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evaluates to -2(-3 * (-1 + -2)) = -29 = -512. |
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### Input |
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Input begins with an integer **T**, the number of polynomials. For each |
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polynomial, there is first a line containing the integer **N**, the degree of |
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the polynomial. Then, **N**+1 lines follow. The _i_th of these lines contains |
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the integer **Pi-1**. |
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### Output |
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For the _i_th polynomial, print a line containing "Case #_i_: **K**", where |
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**K** is the number of distinct real values of **x** for which the polynomial |
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evaluates to 0. Then print **K** lines, each containing such a value of **x**, |
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in increasing order. |
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Absolute and relative errors of up to 10-6 will be ignored in the x-intercepts |
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you output. However, **K** must be exactly correct. |
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### Constraints |
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1 ≤ **T** ≤ 200 |
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0 ≤ **N** ≤ 50 |
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-50 ≤ **Pi** ≤ 50 |
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**PN** ≠ 0 |
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### Explanation of Sample |
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In the first case, the polynomial is 1 * x1 \+ 1 * x0. With the order of |
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operations reversed, this is evaluated as (1 * x)(((1 + 1) * x)0), which is |
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equal to 0 only when x = 0. |
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In the second case, the polynomial does not evaluate to 0 for any real value |
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x. |
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