C++ array indexing starts at 0, so:
Is going to skip the first entry in all your arrays.Code:for( i =1;i<n;i++) { scanf("%d \t %d \t %d \t",&number,&number2,&number3); rollno[i] = number; sub1[i] = number2; sub2[i] = number3;x` total[i] = sub1[i]+sub2[i]; avg[i] = (total[i] / 2) * 100 ; grade[i] = gradecal(avg[i]); }