题目链接

import java.io.BufferedInputStream;
import java.io.InputStreamReader;
import java.util.Scanner;
/**
 * P1957 
 * @author suystar_bg
 * */
public class Main{
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int i = scanner.nextInt();
        scanner.nextLine(); // 消耗换行符

        char lastOperation = ' ';
        int lastResult = 0;

        for (int j = 0; j < i; j++) {
            String[] input = scanner.nextLine().split(" ");
            char operation;
            int number1, number2;

            if (input.length == 3) {
                // 三个数据，第一个是运算符，后两个是数字
                operation = input[0].charAt(0);
                number1 = Integer.parseInt(input[1]);
                number2 = Integer.parseInt(input[2]);
            } else {
                // 两个数据，假设与上一个算式的运算类型相同
                operation = lastOperation;
                number1 = lastResult;
                number2 = Integer.parseInt(input[0]);
            }

            int result;
            switch (operation) {
                case 'a':
                    result = number1 + number2;
                    break;
                case 'b':
                    result = number1 - number2;
                    break;
                case 'c':
                    result = number1 * number2;
                    break;
                default:
                    throw new IllegalArgumentException("你谷数据错了。");
            }

            String expression = number1 + (operation == 'a' ? "+" : operation == 'b' ? "-" : "*") + number2 + "=" + result;
            int length = expression.length();

            System.out.println(expression);
            System.out.println(length);

            lastOperation = operation;
            lastResult = result;
        }

        scanner.close();
    }
}