アルゴリズムノート練習6.1 vector問題A:【PAT A 1039】Course List for Studio

アルゴリズムノート練習問題解合集
タイトルリンク
タイトル
タイトルはZhejiang University has 40000 students and provides 2500 courses.Now given the student name lists of all the courses, you are supposed to output the registered course list for each student who comes for a query.
Each input file contains one test caseを入力します.For each case, the first line contains 2 positive integers: N (<=40000), the number of students who look for their course lists, and K (<=2500), the total number of courses. Then the student name lists are given for the courses (numbered from 1 to K) in the following format: for each course i, first the course index i and the number of registered students Ni (<= 200) are given in a line. Then in the next line, Ni student names are given. A student name consists of 3 capital English letters plus a one-digit number. Finally the last line contains the N names of students who come for a query. All the names and numbers in a line are separated by a space.
出力For each test case,print your results in N lines.Each line corresponds to one student, in the following format: first print the student’s name, then the total number of registered courses of that student, and finally the indices of the courses in increasing order. The query results must be printed in the same order as input. All the data in a line must be separated by a space, with no extra space at the end of the line.
サンプル入力

11 5
4 7
BOB5 DON2 FRA8 JAY9 KAT3 LOR6 ZOE1
1 4
ANN0 BOB5 JAY9 LOR6
2 7
ANN0 BOB5 FRA8 JAY9 JOE4 KAT3 LOR6
3 1
BOB5
5 9
AMY7 ANN0 BOB5 DON2 FRA8 JAY9 KAT3 LOR6 ZOE1
ZOE1 ANN0 BOB5 JOE4 JAY9 FRA8 DON2 AMY7 KAT3 LOR6 NON9

サンプル出力

ZOE1 2 4 5
ANN0 3 1 2 5
BOB5 5 1 2 3 4 5
JOE4 1 2
JAY9 4 1 2 4 5
FRA8 3 2 4 5
DON2 2 4 5
AMY7 1 5
KAT3 3 2 4 5
LOR6 4 1 2 4 5
NON9 0

構想
自分で書いたときはハッシュもSTLもうまく使えなかったし、完全にC言語の思考だったので、リュウの構想とコードを参考にしました.
学んだこと:

ハッシュを覚えて、ハッシュを覚えて、ハッシュを覚えています.

の大きな配列はグローバル変数に開く.

vector配列に比べて配列が長くなる利点があるため、長さが変わらないと判断したデータは配列を用いることができ、脳用vectorを用いる必要はない.

vectorを使用した場合は、セットの.push_back()でデータを挿入し、.size()で要素の個数を取得し、C言語のarray[cnt++] = value;を使用しないでください.

sort関数は、cmpを書かずにデフォルトのインクリメントソートを書くことができます.

コード#コード#

#include 
#include 
#include 
#include 
using namespace std;

int string_to_int(char *str) {
	int ret = 0;
	for (int i = 0; i < 3; ++i)
		ret = ret * 26 + str[i] - 'A';
	ret = ret * 10 + str[3] - '0';
	return ret;
}

const int MAX = 26 * 26 * 26 * 10 + 10;
vector<int> students[MAX];	//           

int main() {
	int n, k;
	char name[5];
	while (scanf("%d %d", &n, &k) != EOF) {
		memset(students, 0, sizeof(students));
		for (int i = 0; i != k; ++i) {
			int cno, stuNum;
			scanf("%d %d", &cno, &stuNum);
			for (int j = 0; j != stuNum; ++j) {
				scanf("%s", name);
				students[string_to_int(name)].push_back(cno);
			}
		} 
		for (int i = 0; i != n; ++i) {
			scanf("%s", name);
			int no = string_to_int(name);
			printf("%s %d", name, students[no].size());
			sort(students[no].begin(), students[no].end()); 
			for (auto it = students[no].begin(); it != students[no].end(); ++it)
				printf(" %d", *(it));
			putchar('
'); 
		} 
	} 
	return 0;
}