At present, there are two main ways to fill in the college entrance examination volunteers in all provinces in China. One is the sequential voluntary filing method, which was widely used in the past, and the other is the parallel volunteer admission method, which is being popularized in various provinces. At present, most provinces adopt parallel volunteer admission method in most batches. The operation process of filing is as follows: the first round of filing, the file of the first volunteer candidate is filed. Before filing, the computer will sort the candidates who apply for the same institution for the first time from high to low for all institutions that participate in the same batch of admission, and each institution will queue up. According to the enrollment plan of colleges and universities, the files of the first volunteer candidates are invested in these colleges and universities according to the proportion of high scores to low scores. The second round of filing, the second volunteer candidate file. In the lowest control line of the same batch, all colleges and universities with full first choice no longer put candidates' second choice files on it. If the students of the first volunteer candidates in a university are insufficient, the candidates who apply for the second volunteer can be sorted from high score to low score according to their grades, and the candidates' second volunteer files can be sent to the school from high score to low score according to the number of vacancies in the university. The third round of filing, the third volunteer file of candidates. On the lowest control line of the same batch, any institution that fails to complete the project after the first and second volunteers file will continue to file the third volunteer in the same way until the school files in proportion. It can be seen that in the voluntary priority filing method, when any group of non-first volunteer candidates apply for a school, even if their scores are high, it is only effective when the number of first volunteer candidates in the school is insufficient. That is to say, only when the number of first-choice candidates in the school is not satisfied (that is, the first-choice candidates are short of files) can non-first-choice candidates file with the school. It can be seen how important it is to report the first choice! The disadvantage of this method is that it is easy to cause high-scoring candidates to fall off the list. (2) The principle of parallel volunteer's bidding method is: giving priority to achievements and following wishes. Before an enrollment batch is filed, the candidates of the same kind in the province (literature, science, sports and art) are sorted from high score to low score according to the total score of the college entrance examination. Then, starting with the first candidate, put the candidates in their college volunteers in turn. The specific operation process of filing is as follows: the first candidate. Since all the candidates have not started to file at this time, it is obvious that no matter which university the first candidate chooses to apply for, his file will be successfully submitted to the target institution. ..... the nth candidate. If the student's plan for the first voluntary college is not full this year, his file will be invested in the first voluntary college. If the first voluntary college is full, search whether the second voluntary college is full, and if not, send its file to the second voluntary college; If the candidate's second volunteer college is full, search whether the third volunteer college is full, and handle the third volunteer in exactly the same way as the second volunteer ... After all the volunteers of the candidate are searched, if the student's file is still not filed, all the volunteers reported by the student will be invalid, and the batch filing of the student will end. For all candidates after N+ 1, the computer will handle them in the same way. Under the parallel volunteer model, although the candidates' first, second and third choices are tied, the computer can only search whether the candidates can file from the first choice. Only when the first choice fails, the computer will search for the second choice, and so on, so the order of filling in the volunteers is more important.