E4 F grading

/*
 Author: Cao Beijian(37509)
 Result: AC Submission_id: 4278539
 Created at: Tue Apr 05 2022 21:26:25 GMT+0800 (China Standard Time)
 Problem: 5479  Time: 5 Memory: 1756
*/

#include <stdio.h>
#include <math.h>
double max_f64(double *arr, int n){
    int i;
    double ans = arr[0];
    for(i = 1; i < n; i++){
        if(arr[i] > ans){
            ans = arr[i];
        }
    }
    return ans;
}
int main(){
    int n, i, j, m;
    scanf("%d", &n);
    int id[64] = { 0 };
    double gpajq[64] = { 0 }, rykjq[64] = { 0 }, credits[64] = { 0 };
    double gpasum, honorsum, honorcnt;
    double M1, M2, M3;
    double grade, credit;
    int honor;
    for(i = 0; i < n; i++){
        gpasum = 0; honorcnt = 0; honorsum = 0;
        scanf("%d%d", id + i, &m);
        for(j = 0; j < m; j++){
            scanf("%lf%lf%d", &credit, &grade, &honor);
            if(grade >= 60.){
                gpasum += (credit * (4. - 3. * pow(100 - grade, 2) / 1600.));
            }
            credits[i] += credit;
            if(honor){
                honorsum += grade * credit;
                honorcnt += credit;
            }
        }
        gpajq[i] = gpasum / credits[i];
        rykjq[i] = honorsum / honorcnt;
    }
    M1 = max_f64(gpajq, n);
    M2 = max_f64(rykjq, n);
    M3 = max_f64(credits, n);
    for(i = 0; i < n; i++){
        printf("%d %.4f\n", id[i], gpajq[i] / M1 * 50. + rykjq[i] / M2 * 30. + credits[i] / M3 * 20.);
    }
    return 0;
}