About a C language design question, the master enters 50

main()

Enter a long integer and output a long integer*

int i,k,a[100];

printf("Enter the number of digits:");

scanf("%d",&a[0]);

k=a[0];

printf("Enter each digit of the long integer in turn:");

for(i=k;i>0;i--)

scanf("%d",&a[i]);

printf("The long integer is:");

for(i=k;i>0;i--)

printf("%d",a[i]);

main()

Add 2 long integers*

int i,k,n,a[100],b[100];

printf("Enter the number of digits of two long integers, separated by commas");

scanf("%d,%d",&a[0],&b[0]);

k=a[0];

n=b[0];

printf("Enter each of the 2 long integers in turn:");

for(i=k;i>0;i--)

scanf("%d",&a[i]);

for(i=n;i>0;i--)

scanf("%d",&b[i]);

if(k>=n){

for(i=1;i<=n;i++)a[i]+=b[i];

printf("The long integer after adding is:");

for(i=k;i>0;i--)printf("%d",a[i]);

else{for(i=1;i<=k;i++)b[i]+=a[i];

printf("The long integer after adding is:");

for(i=n;i>0;i--)printf("%d",b[i]);

main()

Convert to 16 decimal output*

int i,j,k,m,a[100],b[100];

printf("Enter the number of digits:");

scanf("%d",&a[0]);

k=a[0];

printf("Enter each digit of the long integer in turn:");

for(i=k;i>0;i--)

scanf("%d",&a[i]);

m=a[1];

for(i=2;i<=k;i++)

m+=a[i]*10*(i-1);

for(i=0;m==0;i++)

b[i]=m%16;

m/=16;

j=i; for(i=0;i=0;i--)if(b[i]>9)printf("%c",b[i]);

else printf("%d",b[i]);

Kunming Institute of Technology??? Hehe.

answer:

1: Right. The reason is that the variables directly defined after the struct are struct variables, and here the data is directly defined, then t[20] is the struct array;

There are generally three ways to define a struct definition variable:

First, the direct definition method;

second, the method of defining the name of the structure;

third, the typedef definition method;

2: False. Here, my(x,y) x*y, and when the macro is called, my(2+3,5), then the system will change the x*y of the my macro to x2+3*5, and the correct answer is 17 after the system executes

If you want the answer to be 25, you can change the way you call the macro to: my((2+3),5) so that the answer is 25

p+2) represents the starting address of the third column in a, while *(p+2)+3 represents the address of the element in the fourth column of the third row, and finally *(*p+2)+3) represents the value of the element in the fourth column of the third row, which is a[2][3] in the title

By the way, the array element subscript in c starts at 0 and the last element is n-1.

Personal understanding, if there is a mistake, please correct, thank you!