1028 List Sorting (25 分)

#include<iostream>
#include<string>

using namespace std;

const int N = 100010;

struct student{
    string id, name;
    int grade;
    
    bool operator!=(const student &s) const{
        return id != s.id;
    }
    
}s[N];

int n, c;

int cmp(student &a, student &b, int c){
    if(c == 2 && a.name != b.name) return a.name < b.name;
    if(c == 3 && a.grade != b.grade) return a.grade < b.grade;
    return a.id < b.id;
}

void quick_sort(int l, int r, int c){
    if(l >= r) return;
    
    int i = l - 1, j = r + 1;
    student x = s[l + r >> 1];
    
    while(i < j){
        do i ++; while(cmp(s[i], x, c));
        do j --; while(!cmp(s[j], x, c) && s[j] != x);
        if(i < j) swap(s[i], s[j]);
    }
    
    quick_sort(l, j, c);
    quick_sort(j + 1, r, c);
}

int main(){
    cin >> n >> c;
    
    for(int i = 0; i < n; i ++){
        string id, name;
        int grade;
        
        cin >> id >> name >> grade;
        s[i] = {id, name, grade};
    }

    
    quick_sort(0, n - 1, c);
    
    for(int i = 0; i < n; i ++)
        cout << s[i].id << ' ' << s[i].name << ' ' << s[i].grade << endl;
        
    return 0;
}