题解 | 多项式输出 c#

using System;
using System.Collections.Generic;
public class Program {
    public static void Main() {
        int.TryParse(Console.ReadLine(), out int n);
        string[] inputs = (Console.ReadLine() ?? "").Split(' ');
        string parts = "";

        for (int i = 0; i < inputs.Length; i++) {
            int.TryParse(inputs[i], out int currInt);

            if (currInt == 0) {
                continue;
            }
            //第一个数字
            if (i == 0) {
                if (currInt == 1 || currInt == -1) {
                    string numStr = null;
                    if (currInt == -1) {
                        numStr = "-";
                    } else if (currInt == 1) {
                        numStr = "";
                    }
                    parts += $"{numStr}x^{inputs.Length - i - 1}" ;
                } else {
                    string numStr = currInt.ToString();
                    parts += $"{numStr}x^{inputs.Length - i - 1}";
                }
            }
            //最后一个数字
            else if (i == inputs.Length - 1) {
                string numStr = null;
                if (currInt == 1) {
                    numStr = "+1";
                    parts += numStr;
                } else if (currInt == -1) {
                    numStr = "-1";
                    parts += numStr;
                } else {
                    numStr = (currInt > 0) ? ("+" + currInt.ToString()) : currInt.ToString();
                    parts += numStr;
                }
            }
            //中间的数字
            else {
                // string numStr = (currInt > 0) ? ("+" + currInt.ToString()) : currInt.ToString();
                string numStr;
                if (currInt > 0) {
                    numStr =  "+" + currInt.ToString();
                } else {
                    numStr = currInt.ToString();
                }
                if (currInt == 1) {
                    numStr = "+";
                }
                if (currInt == -1) {
                    numStr = "-";
                }
                int cifang = inputs.Length - i - 1;
                string suffix = "";
                if (cifang == 1) {
                    suffix = "";
                } else {
                    suffix = "^" + (inputs.Length - i - 1).ToString();
                }
                parts += $"{numStr}x{suffix}";
            }
        }
        Console.WriteLine(parts);
    }
}