7-37 模擬EXCEL排序 (25分) c++

用vector配合string進行儲存，函數指針pfun根據flag值指向對應的比較函數，排序後輸出。

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

using namespace std;

struct student {
	string num;
	string name;
	int score = 0;
};

vector<student>v;

bool num(const student a, const student b) { if (a.num > b.num) return false; return true; }
bool name(const student a, const student b) { if (a.name > b.name || (a.name == b.name && a.num > b.num)) return false; return true;}
bool score(const student a, const student b) { if (a.score > b.score || (a.score == b.score && a.num > b.num)) return false; return true;}

int main(void)
{
	int N, flag;
	scanf("%d %d", &N, &flag);

	bool (*pfun) (const student, const student);
	if (flag == 1)pfun = num;
	else if (flag == 2)pfun = name;
	else pfun = score;

	student s;
	char num[7], name[9];
	for (int i = 0; i < N; i++) {
		scanf("%s %s %d", num, name, &s.score);
		s.num = num;
		s.name = name;
		v.push_back(s);
	}

	sort(v.begin(), v.end(), *pfun);

	for (int i = 0; i < N; i++) {
		printf("%s %s %d\n", v[i].num.c_str(), v[i].name.c_str(), v[i].score);
	}

	return 0;
}