C language daily practice (4)

C Exercise Example 9

Topic: Request to output a chess board.

Program analysis: The chess board consists of 64 black and white grids, divided into 8 rows and 8 columns. Use i to control the rows, j to control the columns, and control whether to output black squares or white squares according to the change of the sum of i+j.

Program source code:

#include<stdio.h>

int main()
{
    int i,j;
    for(i=0;i<8;i++)
    {
        for(j=0;j<8;j++)
            if((i+j)%2==0)
                printf("%c%c",219,219);
            else printf("  ");
        printf("\n");
    }
    return 0;
}

The output result of the above example is:

 C Exercise Example 10

Topic: Classical problem (rabbits give birth to babies): There is a pair of rabbits, and they give birth to a pair of rabbits every month from the third month after birth. After the rabbits grow to the third month, they give birth to a pair of rabbits every month. If Even if the rabbits don't die, what is the total number of rabbits every month? (40 months before export is sufficient)

Program analysis: The pattern of rabbits is the sequence 1,1,2,3,5,8,13,21...., that is, the next month is the sum of the previous two months (starting from the third month).

Program source code:

#include<stdio.h>

int main()
{
    int f1=1,f2=1,i;
    for(i=1;i<=20;i++)
    {
        printf("%12d%12d",f1,f2);
        if(i%2==0) printf("\n");
        f1=f1+f2;
        f2=f1+f2;
    }
    
    return 0;
}

The output result of the above example is:

           1           1           2           3
           5           8          13          21
          34          55          89         144
         233         377         610         987
        1597        2584        4181        6765
       10946       17711       28657       46368
       75025      121393      196418      317811
      514229      832040     1346269     2178309
     3524578     5702887     9227465    14930352
    24157817    39088169    63245986   102334155