Dynamic mem and struct

#include <stdio.h>
#include <stdlib.h>
struct course {
	char sub[20];
	int marks;
};

int main(){
	struct course *ptr;
	int i , noOfRecords;
	printf("enter the no of records:");
	scanf("%d",&noOfRecords);
	ptr = (struct course*)malloc(sizeof(struct course)*noOfRecords);
	
	for(i = 0;i<noOfRecords;i++){
		scanf("%s %d",ptr[i].sub,&ptr[i].marks);
	}
	
	for(i = 0;i<noOfRecords;i++){
		printf("%s\t %d\n",ptr[i].sub,ptr[i].marks);
	}
	
}