Equation Solver
Time Limit: 1 Second Memory Limit: 32768 KB
Write a program that can solve linear equations with one variable.Input
The input will contain a number of equations, each one on a separate line. All
equations are strings of less than 100 characters which strictly adhere to the
following grammar (given in EBNF):
Equation := Expression '=' Expression
Expression := Term { ('+' | '-') Term }
Term := Factor { '*' Factor }
Factor := Number | 'x' | '(' Expression ')'
Number := Digit | Digit Number
Digit := '0' | '1' | ... | '9'
Although the grammar would allow to construct non-linear equations like "x*x=25",
we guarantee that all equations occuring in the input file will be linear in
x. We further guarantee that all sub-expressions of an equation will be linear
in x too. That means, there won't be test cases like x*x-x*x+x=0 which is a
linear equation but contains non-linear sub-expressions (x*x).
Note that all numbers occuring in the input are non-negative integers, while
the solution for x is a real number.
Output
For each test case, print a line saying "Equation #i (where i is the number of the test case) and a line with one of the following answers:
If the equation has no solution, print "No solution.".
If the equation has infinitely many solutions, print "Infinitely many solutions.".
If the equation has exactly one solution, print "x = solution" where
solution is replaced by the appropriate real number (printed to six decimals).
Print a blank line after each test case.
Sample Input
x+x+x=10 4*x+2=19 3*x=3*x+1+2+3 (42-6*7)*x=2*5-10
Sample Output
Equation #1 x = 3.333333 Equation #2 x = 4.250000 Equation #3 No solution. Equation #4 Infinitely many solutions.Submit
Source: University of Ulm Local Contest 1997