#P3569. Equation
Equation
Description
Your task is to solve an equation of the form f(x) = 0 where f(x) is written in postfix notation with numbers, operations +, -, *, /, and at most one occurrence of a variable x.
For example, f(x) for an equation (4x + 2)⁄2 = 0 is written as:
4 X * 2 + 2 /
The solution for f(x) = 0 is x = −1⁄2.
Input
The input file consists of a single line with at most 30 tokens separated by spaces. Each token is either:
- a digit from 0 to 9;
- an operation +, -, *, or /;
- an uppercase letter X that denotes variable x.
The input file contains a correct representation of f(x) in postfix notation where token X occurs at most once. There is no division by a constant zero in this equation, that is, there always exists a value of x, such that f(x) can be evaluated without division by zero.
Output
Write to the output file:
- X = p/q if equation f(x) = 0 has a single solution that can be represented with a simple fraction p⁄q, where p and q are coprime integer numbers and q is positive.
- NONE if equation f(x) = 0 has no solution;
- MULTIPLE if equation f(x) = 0 has multiple solutions.
#1 4 X * 2 + 2 / #2 2 2 * #3 0 2 X / *
#1 X = -1/2 #2 NONE #3 MULTIPLE
Source
Northeastern Europe 2007