ex2.java

该程序可将一个四则混合运算分解成一组四元式指令。

						System.out.println(string);
					}
					
					for(int k = 1;k < operator3.Get_suffix() - operator1.Get_suffix();k++) {
						str = str.concat("T");//将处理过的数据和操作符置换成字符T
						suffix[k + operator1.Get_suffix()] = NO;
					}
					NO++;
					
					//合并成新的表达式，未处理部分保持不变
					str = str3.concat(str);
					expression = str.concat(str4);
					
					//System.out.println(operator2.Get_op());
					list.remove(1);
				}
				else if(pri1 < pri2 && pri2 < pri3) {
					String str1 = expression.substring(operator2.Get_suffix()+1,operator3.Get_suffix());
					String str2 = expression.substring(operator3.Get_suffix()+1);
					String str3 = expression.substring(0,operator2.Get_suffix()+1);
					String str = new String();
					
					for(int k = 0;k < str1.length();k++) {
						if(str1.charAt(k) == '(') {
							str1 = str1.substring(k + 1);//消除括号
							k--;
						}
					}
					for(int k = 0;k < str2.length();k++) {
						if(str2.charAt(k) == ')') {
							str2 = str2.substring(0,k);//消除括号
						}
					}
					/*
					System.out.println(expression);
					for(int k = 0;k < suffix.length;k++) {
						System.out.print(suffix[k]);
					}
					System.out.println();
					*/
					for(int k = 1;k < str2.length() + operator3.Get_suffix() - operator2.Get_suffix();k++) {
						if(expression.charAt(k + operator2.Get_suffix()) != 'T') {
							suffix[k + operator2.Get_suffix()] = NO;//修改四元式的结果表示符号的下标数组中的相应元素
						}
					}
					
					//当前要处理的操作符左右两边的数据都为已经处理过的结果
					if(expression.charAt(operator3.Get_suffix() - 1) == 'T' && expression.charAt(operator3.Get_suffix() + 1) == 'T') {
						String string = "("+operator3.Get_op()+","+"T"+suffix[operator3.Get_suffix() - 1]+","+"T"+suffix[operator3.Get_suffix() + 1]+","+"T"+suffix[operator3.Get_suffix()]+")";
						list1.add(string);
						System.out.println(string);
					}
					
					//当前要处理的操作符左边的数据都为已经处理过的结果
					else if(expression.charAt(operator3.Get_suffix() - 1) == 'T') {
						String string = "("+operator3.Get_op()+","+"T"+suffix[operator3.Get_suffix() - 1]+","+str2+","+"T"+suffix[operator3.Get_suffix()]+")";
						list1.add(string);
						System.out.println(string);
					}
					
					//当前要处理的操作符右边的数据都为已经处理过的结果
					else if(expression.charAt(operator3.Get_suffix() + 1) == 'T') {
						String string = "("+operator3.Get_op()+","+str1+","+"T"+suffix[operator3.Get_suffix() + 1]+","+"T"+suffix[operator3.Get_suffix()]+")";
						list1.add(string);
						System.out.println(string);
					}
					
					//当前要处理的操作符左右两边的数据都未被处理过
					else {
						String string = "("+operator3.Get_op()+","+str1+","+str2+","+"T"+NO+")";
						list1.add(string);
						System.out.println(string);
					}
					
					for(int k = 1;k < str2.length() + operator3.Get_suffix() - operator2.Get_suffix();k++) {
						str = str.concat("T");//将处理过的数据和操作符置换成字符T
						suffix[k + operator2.Get_suffix()] = NO;
					}
					NO++;
					expression = str3.concat(str);//合并成新的表达式，未处理部分保持不变
					//System.out.println(expression);
					//System.out.println(operator3.Get_op());
					list.remove(2);
				}
			}
			else if(list.size() >= 4) {
				for(int j = 0;j < list.size()-2;j++) {
					Operator operator1 = (Operator)list.get(j);//左边的符号
					Operator operator2 = (Operator)list.get(j+1);//中间的符号
					Operator operator3 = (Operator)list.get(j+2);//右边的符号
					int pri1 = operator1.Get_pri();
					int pri2 = operator2.Get_pri();
					int pri3 = operator3.Get_pri();
					if(pri1 < pri2 && pri2 >= pri3) {
						String str1 = expression.substring(operator1.Get_suffix()+1,
								operator2.Get_suffix());
						String str2 = expression.substring(operator2.Get_suffix()+1,
								operator3.Get_suffix());
						String str3 = expression.substring(0,operator1.Get_suffix()+1);
						String str4 = expression.substring(operator3.Get_suffix());
						String str = new String();
						
						for(int k = 0;k < str1.length();k++) {
							if(str1.charAt(k) == '(') {
								str1 = str1.substring(k + 1);//消除括号
								k--;
							}
						}
						for(int k = 0;k < str2.length();k++) {
							if(str2.charAt(k) == ')') {
								str2 = str2.substring(0,k);//消除括号
								//k--;
							}
						}
						/*
						System.out.println(expression);
						for(int k = 0;k < suffix.length;k++) {
							System.out.print(suffix[k]);
						}
						System.out.println();
						*/
						for(int k = 1;k < operator3.Get_suffix() - operator1.Get_suffix();k++) {
							if(expression.charAt(k + operator1.Get_suffix()) != 'T') {
								suffix[k + operator1.Get_suffix()] = NO;//修改四元式的结果表示符号的下标数组中的相应元素
							}
						}
						
						//当前要处理的操作符左右两边的数据都为已经处理过的结果
						if(expression.charAt(operator2.Get_suffix() - 1) == 'T' && expression.charAt(operator2.Get_suffix() + 1) == 'T') {
							String string = "("+operator2.Get_op()+","+"T"+suffix[operator2.Get_suffix() - 1]+","+"T"+suffix[operator2.Get_suffix() + 1]+","+"T"+suffix[operator2.Get_suffix()]+")";
							list1.add(string);
							System.out.println(string);
						}
						
						//当前要处理的操作符左边的数据都为已经处理过的结果
						else if(expression.charAt(operator2.Get_suffix() - 1) == 'T') {
							String string = "("+operator2.Get_op()+","+"T"+suffix[operator2.Get_suffix() - 1]+","+str2+","+"T"+suffix[operator2.Get_suffix()]+")";
							list1.add(string);
							System.out.println(string);
						}
						
						//当前要处理的操作符右边的数据都为已经处理过的结果
						else if(expression.charAt(operator2.Get_suffix() + 1) == 'T') {
							String string = "("+operator2.Get_op()+","+str1+","+"T"+suffix[operator2.Get_suffix() + 1]+","+"T"+suffix[operator2.Get_suffix()]+")";
							list1.add(string);
							System.out.println(string);
						}
						
						//当前要处理的操作符左右两边的数据都未被处理过
						else {
							String string = "("+operator2.Get_op()+","+str1+","+str2+","+"T"+NO+")";
							list1.add(string);
							System.out.println(string);
						}
						for(int k = 1;k < operator3.Get_suffix() - operator1.Get_suffix();k++) {
							str = str.concat("T");//将处理过的数据和操作符置换成字符T
							suffix[k + operator1.Get_suffix()] = NO;
						}
						NO++;
						
						//合并成新的表达式，未处理部分保持不变
						str = str3.concat(str);
						expression = str.concat(str4);
						
						//System.out.println(operator2.Get_op());
						list.remove(j+1);
						break;//跳出for循环，进入while循环
					}
					else if(pri1 < pri2 && pri2 < pri3) {
						if(j+3 < list.size()) {
							Operator operator4 = (Operator)list.get(j+3);
							int pri4 = operator4.Get_pri();
							if(pri3 < pri4) {
								continue;//结束本次for循环
							}
						}
						else {
							String str1 = expression.substring(operator2.Get_suffix()+1,
									operator3.Get_suffix());
							String str2 = expression.substring(operator3.Get_suffix()+1);
							String str3 = expression.substring(0,operator2.Get_suffix()+1);
							String str = new String();
							
							for(int k = 0;k < str1.length();k++) {
								if(str1.charAt(k) == '(') {
									str1 = str1.substring(k + 1);//消除括号
									k--;
								}
							}
							for(int k = 0;k < str2.length();k++) {
								if(str2.charAt(k) == ')') {
									str2 = str2.substring(0,k);//消除括号
								}
							}
							/*
							System.out.println(expression);
							for(int k = 0;k < suffix.length;k++) {
								System.out.print(suffix[k]);
							}
							System.out.println();
							*/
							for(int k = 1;k < str2.length() + operator3.Get_suffix() - operator2.Get_suffix();k++) {
								if(expression.charAt(k + operator2.Get_suffix()) != 'T') {
									suffix[k + operator2.Get_suffix()] = NO;//修改四元式的结果表示符号的下标数组中的相应元素
								}
							}
							
							//当前要处理的操作符左右两边的数据都为已经处理过的结果
							if(expression.charAt(operator3.Get_suffix() - 1) == 'T' && expression.charAt(operator3.Get_suffix() + 1) == 'T') {
								String string = "("+operator3.Get_op()+","+"T"+suffix[operator3.Get_suffix() - 1]+","+"T"+suffix[operator3.Get_suffix() + 1]+","+"T"+suffix[operator3.Get_suffix()]+")";
								list1.add(string);
								System.out.println(string);
							}
							
							//当前要处理的操作符左边的数据都为已经处理过的结果
							else if(expression.charAt(operator3.Get_suffix() - 1) == 'T') {
								String string = "("+operator3.Get_op()+","+"T"+suffix[operator3.Get_suffix() - 1]+","+str2+","+"T"+suffix[operator3.Get_suffix()]+")";
								list1.add(string);
								System.out.println(string);
							}
							
							//当前要处理的操作符右边的数据都为已经处理过的结果
							else if(expression.charAt(operator3.Get_suffix() + 1) == 'T') {
								String string = "("+operator3.Get_op()+","+str1+","+"T"+suffix[operator3.Get_suffix() + 1]+","+"T"+suffix[operator3.Get_suffix()]+")";
								list1.add(string);
								System.out.println(string);
							}
							
							//当前要处理的操作符左右两边的数据都未被处理过
							else {
								String string = "("+operator3.Get_op()+","+str1+","+str2+","+"T"+NO+")";
								list1.add(string);
								System.out.println(string);
							}
							
							for(int k = 1;k < str2.length() + operator3.Get_suffix() - operator2.Get_suffix();k++) {
								str = str.concat("T");//将处理过的数据和操作符置换成字符T
								suffix[k + operator2.Get_suffix()] = NO;
							}
							NO++;
							expression = str3.concat(str);//合并成新的表达式，未处理部分保持不变
							System.out.println(expression);
							//System.out.println(operator3.Get_op());
							list.remove(j+2);
							break;//跳出for循环，进入while循环
						}
					}
				}
			}
			i++;
			if(i == size) {
				break;//跳出while循环
			}
		}
		//System.out.println(list.size());
	}
	
	public LinkedList Get_list() {//以列表的形式返回所有的四元式
		return list1;
	}

}