チーム数、ブロック数、乱数シード、チームid、チーム名（空白不可）

block_league.cpp

#include <iostream>
#include <random>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>

using namespace std;

struct team {
	int id;
	string name;

	team() {
		id = 0;
		name = "";
	}
	team(int in_id, string in_name) {
		id = in_id;
		name = in_name;
	}
	bool operator<(const team& a) const {
		return id < a.id;
	}
	bool operator==(const team& a) const {
		return id == a.id && name == a.name;
	}
};

// チーム総数
int team_sum;
// ブロック数
int block;
// 乱数シード
int rand_seed;
// チーム一覧を格納する配列
vector <team> teams;
// ブロックごとのチームを格納する配列
vector < vector <team> > array_block_team;

string view(team a)
{
	return (to_string(a.id) + ", " + a.name);
}

void view_block(vector <team> a, char c)
{
	cout << "*** " << c << " block !start! *** " << endl;
	for (int i = 0; i < a.size(); i++){
		cout << view(a[i]) << endl;;
	}
	cout << "*** " << c << " block !end! *** " << endl << endl;;
	return;
}

string game_view(team a, team b)
{
	return view(a) + ", vs, " + view(b);
}

void league(vector <team> input, char c)
{
	vector <team> start = input;
	cout << "*** " << c << " block league !start! *** " << endl;
	while (1){
		for (int right = 0, left = input.size() - 1; right < left; right++, left--){
			cout << game_view(input[right], input[left]) << ", ";
		}
		puts("");
		rotate(input.begin(), input.begin() + 1, input.end() - 1);
		if (start == input) break;
	}
	cout << "*** " << c << " block league !end! *** " << endl << endl;;
	return;
}

int main(void)
{
	team input;
	team none(-1, "none");

	cout << "チーム総数 : "; cin >> team_sum; puts("");
	cout << "ブロック数 : "; cin >> block; puts("");
	cout << "乱数シード : "; cin >> rand_seed; puts("");

	// ブロックごとのチーム数 切り上げ
	int block_team = (team_sum + (block - 1)) / block;

	printf("ブロックごとのチーム数は最大で %d チーム\n", block_team);

	for (int i = 0; i < team_sum; ++i){
		cin >> input.id >> input.name;
		teams.push_back(input);
	}

	cout << block_team * block << endl;

	sort(teams.begin(), teams.end());
	// view_all();
	// shuffle(teams.begin(), teams.end(), mt19937(rand_seed));

	array_block_team.resize(block);
	int cnt = 0;
	for (int i = 0; i < block_team * block; i++){
		if (i < team_sum){
			array_block_team[cnt].push_back(teams[i]);
		}
		else {
			array_block_team[cnt].push_back(none);
		}
		cnt++;
		cnt %= block;
	}

	for (int i = 0; i < 2; i++){
		for (int j = 0; j < 4; j++){
			cout << view(array_block_team[i][j]) << endl;
		}
	}

	for (int i = 0; i < block; ++i){
		view_block(array_block_team[i], (char)(i + 'A'));
		league(array_block_team[i], (char)(i + 'A'));
	}



	return 0;
}