How to prevent stack smashing detected?

Question

I am trying to write a program to get student data (student id, subject results) from user input and align them based on their total marks. But when I try to input till the 5th student the stack smashing detected the error that occured. And I can't find a way to solve this problem...

It would be really helpful if anyone can give me some advice about it. Thanks in advance

My code: h file

#include <string>
#include <iostream>
using namespace std;
class student
{
    private:
        char id[100];
        int eng, math, jan, total;
    public:
        void getInput(void);//ユーザーから学生のデータを入力してもらう
        void putInput(void);//最後の結果を表示する
        friend void sort(student std[]);//総得点の高い順に各人のデータを並べ替える
        friend void avg(student std[]);//各科目と総得点の平均値を計算する
};

cpp file

#include <string>
#include <iostream>
#include "report1.h"
using namespace std;
#define MAX 10

void student::getInput(void)//ユーザーから学生のデータを入力してもらう
{
    cout << "IDを入力してください:";
    cin >> id;
    cout << "英語の点数:";
    cin >> eng;
    cout << "数学の点数:";
    cin >> math;
    cout << "国語の点数:";
    cin >> jan;
  
    total = eng + math + jan;
}

void student::putInput(void)//最後の結果を表示する
{
    cout << id << "\t" << eng << "\t" << math << "\t" << jan << "\t" << total << endl;
}

void sort(student std[])//総得点の高い順に各人のデータを並べ替える
{
    int i, j;

    for ( i = 0; i < MAX-1; i++)
    {
        for ( j = i+1; j < MAX; j++)
        {
            if (std[i].total < std[j].total)//一つ後ろのデータが確認中のデータより大きいなら、並べ替える
            {
                student temp;
                temp = std[i];
                std[i] = std[j];
                std[j] = temp;
            } 
        }
    }
}

void avg(student std[])//各科目と総得点の平均値を計算する
{
    int i;
    int eng_total, math_total, jan_total, total_total;
    double eng_avg, math_avg, jan_avg, total_avg;
    eng_total = 0;
    math_total = 0;
    jan_total = 0;
    total_total = 0;

    for ( i = 0; i < MAX; i++)
    {
        eng_total += std[i].eng;
        math_total += std[i].math;
        jan_total += std[i].jan;
        total_total += std[i].total;
    }

    eng_avg = (double)eng_total/MAX;
    math_avg = (double)math_total/MAX;
    jan_avg = (double)jan_total/MAX;
    total_avg = (double)total_total/MAX;

    cout << "Avg\t" << eng_avg << "\t" << math_avg << "\t"  << jan_avg << "\t" << total_avg << endl;
}

int main()
{
    student std[MAX-1];
    int i, j;

    for ( i = 0; i < MAX; i++)
    {
        cout << i+1 << "番目の学生データを入力してください。" << endl;
        std[i].getInput();
    }

    sort(std);

    cout << endl;
    cout << "ID_No" << "\tEng" << "\tMath" << "\tJan" << "\tTotal" << endl;

    for ( i = 0; i < MAX; i++)
    {
        std[i].putInput();
    }

    avg(std);

    return 0;
}