Pat 1036 boys vs girls

#include <cstdio>#include <iostream>#include <cstdlib>#include <algorithm>using namespace std;class Stu {    public:        char name[12];        char id[12];        int grade;        char gender;};bool my_cmp(const Stu* a, const Stu* b) {    return a->grade < b->grade;}void print (vector<Stu*> &stu) {    int len = stu.size();    for (int i=0; i<len; i++) {        printf("%s %d\n", stu[i]->name, stu[i]->grade);    }}int main() {    vector<Stu*> male;    vector<Stu*> female;    int n = 0;    scanf("%d", &n);        for (int i=0; i<n; i++) {        Stu* p = new Stu();        scanf("%s %c %s %d", p->name, &(p->gender), p->id, &(p->grade));                if (p->gender == ‘M‘) {            male.push_back(p);        } else {            female.push_back(p);        }    }    sort(male.begin(), male.end(), my_cmp);    sort(female.begin(), female.end(), my_cmp);    Stu* best = NULL;    Stu* worst= NULL;        if (female.empty()) {        printf("Absent\n");    } else {        best = female[female.size() - 1];        printf("%s %s\n", best->name, best->id);    }    if (male.empty()) {        printf("Absent\n");    } else {        worst = male[0];        printf("%s %s\n", worst->name, worst->id);    }    if (worst == NULL || best == NULL) {        printf("NA\n");    } else {        printf("%d", best->grade - worst->grade);    }    return 0;}

I feel like I have lost my brains. I forgot to upload my_cmp.

Pat 1036 boys vs girls