How to extract polynomial coefficients in Java?

问题

Taking the string -2x^2+3x^1+6 as an example, how how to extract -2, 3 and 6 from this equation stored in the string?

回答1:

Not giving the exact answer but some hints:

• Use replace meyhod:

  replace all - with +-.

• Use split method:

  // after replace effect
  String str = "+-2x^2+3x^1+6"
  String[] arr = str.split("+");
  // arr will contain: {-2x^2, 3x^1, 6}
  

• Now, each index value can be splitted individually:

  String str2 = arr[0];
  // str2 = -2x^2;
  // split with x and get vale at index 0
  

回答2:

    String polynomial= "-2x^2+3x^1+6";
    String[] parts = polynomial.split("x\\^\\d+\\+?");
    for (String part : parts) {
        System.out.println(part);
    }

This should work. Sample output

polynomial= "-2x^2+3x^1+6"
Output:
-2
3
6 
polynomial = "-30x^6+20x^3+3"
Output:
-30
20
3

来源：https://stackoverflow.com/questions/13415573/how-to-extract-polynomial-coefficients-in-java