#include <stdio.h>

typedef struct{
	int id;
	int english;
	int class;
}Student;

void classify(Student data[]);

int main(void) {
	
	Student data[] = {{1,60},{2,80},{3,90},{4,70},{5,50}};
	
	classify(data);
	
	for(int i = 0;i < 5;i ++){
		printf("id:%d class:%d\n",data[i].id,data[i].class);
	}
	return 0;
}

void classify(Student data[]){
	
	for(int i = 0;i < 5;i ++){
		if(data[i].english >= 90){
			data[i].class = 'A';
		}else if(80 <= data[i].english < 90){
			data[i].class = 'B';
		}else if(70 <= data[i].english < 80){
			data[i].class = 'C';
		}else if(60 <= data[i].english < 70){
			data[i].class = 'D';
		}
	}
}