#include <cstdio>#include <cstring>#include <cstdlib>#include <algorithm>using namespace std;class Stu {public:    char id[8];    char name[10];    char grade;};bool cmp_id(const Stu* a, const Stu* b) {    return strcmp(a->id, b->id) < 0;}bool cmp_name(const Stu* a, const Stu* b) {    int res = strcmp(a->name, b->name);    if (res > 0) {        return false;    } else if (res < 0) {        return true;    }    return cmp_id(a, b);}bool cmp_grade(const Stu* a, const Stu* b) {    if (a->grade > b->grade) {        return false;    } else if (a->grade < b->grade) {        return true;    }    return cmp_id(a, b);}int main() {    int N, C;    scanf("%d%d", &N, &C);    vector<Stu*> stus(N, NULL);    for (int i=0; i<N; i++) {        Stu* cur = stus[i] = new Stu();        scanf("%s%s%d", cur->id, cur->name, &(cur->grade));    }        // TODO: use function ptr array    if (C==1) {        sort(stus.begin(), stus.end(), cmp_id);    } else if (C==2) {        sort(stus.begin(), stus.end(), cmp_name);    } else {        sort(stus.begin(), stus.end(), cmp_grade);    }        for (int i=0; i<N; i++) {        printf("%s %s %d\n", stus[i]->id, stus[i]->name, stus[i]->grade);    }    return 0;}