2 人解决,7 人已尝试。
2 份提交通过,共有 10 份提交。
9.4 EMB 奖励。
单点时限: 2.0 sec
内存限制: 256 MB
Write a program that can solve linear equations with one variable.
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 “xx=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 xx-xx+x=0 which is a linear equation but contains non-linear sub-expressions (xx).
Note that all numbers occuring in the input are non-negative integers, while the solution for x is a real number.
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.
x+x+x=10 4*x+2=19 3*x=3*x+1+2+3 (42-6*7)*x=2*5-10
Equation #1 x = 3.333333 Equation #2 x = 4.250000 Equation #3 No solution. Equation #4 Infinitely many solutions.
2 人解决,7 人已尝试。
2 份提交通过,共有 10 份提交。
9.4 EMB 奖励。